This article will go over how to use the Ruleset Editor and the functions of the JavaScript API.

A Note on Security

Our Rulesets function via HTML and a JS API that allows you to write calls that execute functions against our backend. The function calls you have access to in the API can only alter data in the current Campaign, and do not give players access to data in other Campaigns or from Modules that they have not purchased.

The JavaScript code runs inside a hardened sandbox (SES Compartments) that isolates it from the rest of the application. Sandboxed scripts have no access to the network, browser storage, cookies, the DOM, or other users' data — only the explicit Ruleset API and a small set of safe language built-ins (Math, JSON, Date, etc.) are exposed. This ensures macros cannot pull data from other users or produce malicious results. Furthermore, all API calls to the backend are rate-limited to reasonable levels to prevent a user from writing a malicious script. The writing of malicious code is strictly prohibited by our Terms of Service.

Create a Ruleset

To begin creating rulesets, first log in, or from the Campaigns page, click “Ruleset Editor” at the top.

You will be taken to the Ruleset selection page. If you have never created a Ruleset before, this page will be empty.

Click “Create New Ruleset” to begin making or editing an existing Ruleset. A good way to get started is to copy an existing one so you can see examples of other implementations. You can always remove any unnecessary code or settings once you do so. Provide a Name, a Description of the Ruleset, and optionally select a Ruleset to copy data from. You can also start completely fresh.

Click “Create New Ruleset” to begin making or editing an existing Ruleset. A good way to get started is to copy an existing one so you can see examples of other implementations. You can always remove any unnecessary code or settings once you do so. Provide a Name, a Description of the Ruleset, and optionally select a Ruleset to copy data from. You can also start completely fresh.

Once the Ruleset is created you will be navigated to the Records tab of the Editor.

Rulesets are composed of Records, types of data that are defined by the fields that can be edited or changed on the record’s HTML.

The Settings tab of the editor is used for editing important settings of the Ruleset to define how certain VTT functions behave, options for Effects, etc. (more on this later.)

Saving Changes

On both the Records and Settings tab there is a Save button. Be sure to save often if you are not using your own source control! You will be prompted when navigating to a different function if you have not saved, but it is easy to lose changes on accident.

Note: Ruleset code can get quite complex! We recommend that you rely on your own source control such a git and use an editor offline such as Visual Studio Code. Then, copy and paste changes into the editor.

Roll Syntax

Realm VTT's roll parser handles standard dice notation plus a handful of extras for exploding dice, dropping, damage labels, inline colors, and success-count pools. The exact same string works in three places:

• /roll 2d6+3 in chat

• api.roll("2d6+3") from a ruleset script

• api.promptRoll("Attack", "2d6+3") to ask the player before rolling

Basics

Exploding Dice

Append to the die size to make a group explode.

Only the specific group gets the modifier — 1d6+1d4! explodes the d4 and leaves the d6 alone.

Dropping Dice

Dropped dice still show in the chat card, greyed out so players can see what was rolled.

Damage Types / Labels

A space-separated label after a die group tags those dice with a damage type:

1d8 fire + 1d6 cold + 2 lightning

Labels propagate rightward so 1d6 + 1d4 fire makes the whole expression fire damage. An explicit default label means "no damage type, sum normally." Labels show as icons in the chat card and are available to ruleset scripts on each result entry's type field.

Inline Colors

Wrap one or two hex values in brackets to tint a specific die group in the 3D tray and the chat card:

Colors are a visual concern only — they don't change the damage label. So 1d20[#ffffff] default gives you a white die whose damage type is default, and 1d10![#0000ff] + 1d10[#ff0000] + 1d10[#00ff00] rolls three distinct-colored d10s where only the blue one explodes.

For labeled groups from scripts you can also pass a diceColors map in metadata — see the examples below.

Success-Count Pools

Wrap an expression in {...} and follow with >N, <N, or =N to count how many dice met the threshold instead of summing:

The chat card shows the successes count alongside the individual results. ! counts every individual die; !! counts chains. A trailing >N without braces is still the explosion threshold, not a success count.

Using it from scripts

api.roll(rollString, metadata, rollType) — rolls immediately, no prompt.

// Exploding damage with mixed types and labels
api.roll("2d6! fire + 1d4 cold", { source: "fireball" });

// Per-label colors via metadata (alternative to inline [#hex])
api.roll("1d6 hope + 1d6 fear", {
  diceColors: {
    hope: { diceColor: "#4488ff", textColor: "#ffffff" },
    fear: { diceColor: "#ff4444", textColor: "#000000" }
  }
});

// Shadowrun-style success pool
api.roll("{6d6!!}>=8");

api.promptRoll(name, rollString, modifiers, metadata, rollType) — opens the roll dialog first so the player can tweak modifiers before confirming. Same syntax:

api.promptRoll(
  "Longbow Attack",
  "1d20 + 1d8 piercing",
  [{ label: "Advantage", value: "+1d4" }],
  { weapon: "longbow" }
);

api.promptRoll(
  "Exploding Wild Magic",
  "1d100![#9b59b6] arcane",
  [],
  {}
);

Both functions return a promise that resolves after the 3D animation completes, with the full result including per-die values, dropped dice, success count (if any), and resolved totals — ready to feed back into the rest of your ruleset logic.

Records and Lists

All Rulesets must have a Characters type and an NPCs type. These cannot be removed and are listed by default.

From the Records tab you can create new Record types or List types. For both, you will see a Required Fields section and an area to enter the HTML and JavaScript.

Changes in the editor appear after a brief second in the Preview section, which shows you what the Record type looks like in the VTT, and allows you to add Tabs to it (or edit the tabs.)

Records

For each defined Record type you will see a section in the “Compendium” of the VTT that allows users to create new entries of that type. For Records that will be used in a List type (such as Items, Spells, or Abilities) we recommend also including a portrait field in the HTML (more on this later in the Fields section.)

All Records have the following required fields:

• Name: How it is displayed to the players in the VTT

• Type: The underlying “type” used by the backend and when querying for this record type

• Width: The default width of the record window

• Height: The default height of the record window

• Filters: This will define filters that players in the VTT can select in order to quickly search for specific records. In the above example, there is one set for the size field

Record Tabs

All records have the ability to add or edit Tabs. Click the “Add Tab” button above the Preview to add a new tab. Click a tab and click “Edit Tab” to remove Tab, change its position, or rename it.

Each tab has their own HTML and JS code for it. Once clicking on a Tab, enter the HTML and JS for that tab.

Tabs can be hidden or unhidden for a record by setting the data at tabs.${tabName}.hidden = true|false. Example:

```Test_HideUnhide
api.setValue("tabs.Inventory.hidden", !tabs["Inventory"]?.hidden);
```

Lists

Lists are built in a similar way as Records but they are in fact not shown in the Compendium. A List Record Type allows you to define one element of a List of elements that can then be added to a record type. For example, you might have a Items Record Type. And then you might also define an Item List Type. The Item List would be rendered on the Character Sheet so you can create an Inventory of Items.

From the List type you define in the HTML and JS the behavior or one element of the list. Then, when save it when done. Once you want to add that List Type to a Record sheet, go back to that Record type on the Records & Lists selection, then scroll all the way down in the “Fields” section, and click the defined List type. (More on this in the Fields section.) List do not have tabs like records do.

All Lists have the following required fields:

• Name: A display name for the List in the Editor

• Type: The underlying “type” used by the VTT when adding this list to a record

• Width: The default width of the editor preview window (unlike records, this does not affect the element size when rendered)

• Height: The default height of the editor preview window (unlike records, this does not affect the element size when rendered)

• Show Add Button: Enables the ability to Add one-off elements of the list on the record that uses it

• Show Delete Button: Enables the ability to Delete elements from the list on the record that uses it

• Single Row: Renders each element of the list in one row, instead of each being its own row

• Empty List Text: Text to show in the List when rendered without elementgs

• Add Button Text: Text to use in the Add button

• New Item Name: Name to set on all new elements added to the list

• New Item Unidentified Name: All records have an Unidentified Name, and this lets you define the default Unidentified Name when adding elements to this list

• Allowed List Record Types: This sets the default types that can be drag and dropped to the list. Most lists only define one, but there may be cases where you want two different record types to be able to be added to a list.

  • Disable Drop: This disables the drag and drop behavior when allowed list record types are set. This is useful when you want it to default to the icon of an allowed record type on Add of a new item, but wish to handle the Drag and Drop behavior manually (such as in the Drag and Drop script of a record, more on this later.)

  • Stack Duplicates: Enable this setting when you want duplicate entries to be counted more than once, and provide the name of the field used to keep track of the count.

• Order Criteria: Fields that appear in the Record HTML will show up in this dropdown. Select the field you want to sort the list by (such as name, count, etc.) and then whether it is Ascending of Descending. You can provide more than one criteria which is sorts in order. (Example, sorting by name then by count.)

• Filter Criteria: Define filter criteria when you want the list to only show elements that match a specific filter. Select the field, then the operator, then the value you are looking for.

  • Example: Suppose you want a list of Attacks on another tab, and suppose you want to only show Attacks with Weapons from the Inventory that are Equipped. You could add two filters, one for a “type” field and one for an “equipped” field.

  • Dynamic Filters: If you want a filter to be dynamic and defined by another value on the parent record of the list (for example, a dropdown you have added on the record that displays the list) you can set the value to “{path.to.value}”. For example, say you have a dropdown field called “filterValue” you would set this to: “{data.filterValue}”. In this case, a value of an empty string (i.e. ““) will just display all elements.

• Max Length: Use this field when you want to impose a maximum length of the list.

Note: Lists have additional attributes that can be passed to the HTML in which they are entered on the record. See the <list> tag details below in the Fields and HTML API section.

Fields and HTML API

The HTML in Realm VTT is modified to support our support fields. Additionally, each record type can define a “script” and in the script you can put an “onDrop” handler. This will be executed any time a record is dropped to the record.

// onDrop type is a string such as "spells"
// recordLink example
{
  value: {
    _id: 'abc',
    recordType: "spells"
    name: "Ray of Frost
    data: {...}
  },
  tooltip: "Ray of Frost"
}

//onDrop sourceInfo example
{
 type: "list",
 recordType: "items",
 recordId: "abc-123",
 dataPath: "inventory.data.12"
 index: 12
}
//onDrop sourceInfo example from PartySheet
{
 type: "partysheet",
 itemId: "item-123",
}

In the Script of a record type, you make also want to create functions used by the fields within. See an example below for how this might look.

Additionally, the JavaScript executed in Records has an API that be called for VTT functions, see the JavaScript API section for more information.

Record Scripts

Record types can also reference code from a “Common” Script that you define. The Common Script is defined in the “Settings” tab under “Additional Settings.” It is a good idea to place re-used code here, so you do not re-write it across all your Record types!

<script>
  function onDrop(type, recordLink, sourceInfo) {
    if (type === 'spells') {
      onDropSpell(recordLink);
    }
  }

  function onDropSpell(recordLink) {
    // Code here...
  }
  
  function rollInitiative() {
    // Roll initiative for the character
    // Code here ...
  }
</script>

<div style="width: 100%; display: flex; justify-content: flex-end;">
  <button field="rollInitBtn" size="xs" icon="D20" label="Initiative" variant='outline'
    onclick='rollInitiative();'></button>
</div>

Record Styles

The custom tags such as <box> and <stringfield>, etc., do not support the style tag. However, you can inject styles in divs using "style" or by the <style> section of a record.

The class prop is supported on all typical HTML tags as well as the following Realm tags:

• box

• stringfield

• namefield

• numberfield

<style>
  .example {
    background-color: var(--mantine-color-tertiary-filled);
  }
</style>

<div style="width: 100%; display: flex;">
  <box field="itemProps" class="example">
    <stringfield field="type" placeholder="Enter type..."></stringfield>
  </box>
</div>

Record Fields

Here are all the currently supported field types with the HTML.

With the exception of the Name, Unidentified Name, and Portrait, the values for all Fields are stored in the data object of each record. (Example, a character with a number field defined as “hp” will have it stored in data.hp). The following fields are stored directly on each record (i.e. not in data):

• name

• unidentifiedName

• portrait

• locked

Record Metadata

Sometimes you need access to the metadata of a field, for example, manually setting whether a field is hidden. This is stored in the fields section of a record. Example, setting the “hp” value to hidden, is stored in: fields.hp.hidden = true. (More on this later.)

Accessing List Values

Sometimes in the API you need to access or change the value in a list. You can do this using dot notation (more on this later) to the element in the list. Example: The data path to the “equipped” value on the first element of a list called “inventory” would be: data.inventory.0.data.equipped

Colors

Colors for fields use the Mantine color system. Click here to see more information.

Icons

Icons that are available in Realm VTT come from Tabler icons or Game Icons. If the Icon name starts with Icon it is assumed to be Tabler. If it starts with “Gi” it checks for the icon from Game Icons.

Portrait

Description: Allows setting and displaying a portrait for the record. For Characters and NPCs, it also allows setting a Token. Portraits (and Tokens) can be edited when the Record is unlocked by clicking on the Portrait. When set, it can be viewed or shared with players by clicking on the Image icon in the bottom-right.

Attributes:

1. field - The data field to store the portrait, which should always be “portrait” — this cannot be changed

2. All common attributes (see Common Attributes section below)

Example:

<portrait field="portrait" width="150px" height="150px"></portrait>

String Field

Description: Allows setting and displaying a string value on the record.

Attributes:

1. field - The data field to store the string value

2. defaultvalue - Default value if none is set

3. textalign - Text alignment (left, center, right). Aligns the label and the input.

4. multiline - If true, allows multiple lines of text

5. maxrows - Maximum number of rows for multiline input

6. editable - If “true” this field is always editable even if the record is locked.

7. bold - Show the field value in bolder font, if true

8. All common attributes

Example:

<stringfield 
  field="description" 
  label="Description" 
  multiline="true" 
  maxrows="4"
  placeholder="Enter description..."
></stringfield>

Rich Text Field

Description: Allows setting and displaying rich text on the record.

Attributes:

1. field - The data field to store the rich text

2. disablecontrols - If true, hides the formatting controls

3. All common attributes

Example:

<richtextfield 
  field="notes" 
  label="Notes"
  height="300px"
></richtextfield>

Number Field

Description: Allows setting and displaying a number value on the record.

Attributes:

1. field - The data field to store the number

2. minvalue - Minimum allowed value

3. maxvalue - Maximum allowed value

4. maxvaluefield - Used only if maxvalue is not provided, defines a field that stores the max value for this numberfield. Must be another numberfield.

5. showsign - If true, always shows + or - sign

6. defaultvalue - Default value if none is set

7. textalign - Text alignment (left, center, right). Aligns the label and the input.

8. editable - If “true” this field is always editable even if the record is locked. If “false” it is always disabled.

9. bold - Show the field value in bolder font, if true

10. All common attributes

Example:

<numberfield 
  field="modifier" 
  label="Modifier" 
  showsign="true"
  minvalue="-5"
  maxvalue="5"
></numberfield>

Name Field

Description: Special field for displaying and editing the record's name, with support for unidentified states. If on a List type, it is the name of that List element.

Attributes:

1. field - The data field for the name (usually "name")

2. defaultvalue - Default name if none is set

3. textalign - Text alignment (left, center, right)

4. multiline - If true, allows multiple lines

5. maxrows - Maximum number of rows for multiline input

6. bold - Show the field value in bolder font, if true

7. editable - If “true” this field is always editable even if the record is locked. If “false” it is always disabled.

8. All common attributes

<namefield 
  field="name"
  label="Character Name"
  placeholder="Enter name..."
  size="xl"
></namefield>

Record Link

Description: Creates a link to another record.

Note: See the API section for setRecordLink on how to use this field. It expects the value to be a recordLink (like from an onDrop handler.)

Attributes:

1. field - The data field containing the linked record data

2. All common attributes

<recordlink 
  field="weapon"
  label="Equipped Weapon"
></recordlink>

Checkbox

Description: Creates a checkbox for boolean values.

Attributes:

1. field - The data field to store the boolean value

2. All common attributes

Example:

<checkbox 
  field="proficient"
  label="Proficient"
></checkbox>

Radio Button

Description: Creates a radio button for selection within a group.

Attributes:

1. field - The data field to store the selection, should be the same for all radio buttons in the same group

2. All common attributes

Example:

<div>
  <radio 
    field="alignment"
    label="Lawful Good"
    value="lg"
  ></radio>
  <radio 
    field="alignment"
    label="Neutral Good"
    value="ng"
  ></radio>
</div>

Label

Description: Displays static text.

Attributes:

1. textalign - Text alignment (left, center, right)

2. All common attributes

Example:

<label 
  label="Combat Statistics"
  size="lg"
  color="blue"
  textalign="center"
></label>

Divider

Description: Adds a horizontal or vertical line separator.

Attributes:

1. orientation - Direction of the divider ("horizontal" or "vertical")

2. All common attributes

Example:

<divider 
  label="Combat"
  orientation="horizontal"
  size="lg"
></divider>

Tag

Description: Adds a tag that displays text with tooltip descriptions.

Attributes:

1. field - The name of the field containing the name of the tag in the underlying data

2. tooltip - The name of the field containing the tooltip in the underlying data

3. tooltipquery - (optional) If present, we query for a record in the campaign to get the tooltip looking for a record with the same name as the "field" (above) in the underling record

4. tooltipfunction - (optional) If present, we call the given function using the name of the tag as the value, in order to determine what the tooltip should be.

5. variant - Visual style ('default' or 'filled')

6. color - Color of the tag (uses Mantine color system)

7. size - Size of the tag (xs, sm, md, lg, xl)

8. All common attributes

Example:

<tag 
  field="status" 
  tooltip="Current status effect" 
  variant="filled"
  color="blue"
  size="sm"
></tag>

<!-- This will render a tag using the name of the underlying record and query for a "trait" record. If found it will render the tooltip using `trait.data.description` -->
<tag
  field="name"
  color="default"
  tooltipquery='{"type": "traits", "tooltip": "data.description"}'
></tag>

<!-- This will call the function below to get the tag's tooltip. -->
<script>
  function getTraitToolTip(value) {
    switch (value) {
      case "Unholy":
        return "<p>This is <b>bad</b> and evil.</p>";
      case "Weapon":
        return "<p>This is a <b>weapon</b>.</p>";
      default:
        return "";
    }
  }
</script>

<tag
  field="name"
  color="default"
  tooltipfunction="return getTraitToolTip(value);"
></tag>

Dropdown

Description: Creates a dropdown selection menu.

Attributes:

1. field - The data field to store selection

2. options - Array of options (as JSON string)

3. optionsquery - JSON of a query to get data from the backend. This will only get data that exists in the current campaign. Expects JSON string in the format: {"type": "effects", "query": {}} where “type” is a record type (or one defined by the VTT such as ‘effects’) and “query” is a MongoDB style query (if you wish to filter it to specific entries.)

4. optionsfunction - Define a function to call that returns an Array of options. Only used if options and options query not defined. (e.g. “optionsquery=’return someFunction();’” where “someFunction” returns an array in the same format expected by “options.”

5. icon - Icon to display

6. multiselect - Allow multiple selections if true

7. searchable - Enable search functionality if true

8. combo - If "true" indicates that this is a combobox that allows the user to type in their own value.

9. defaultvalue - Default selected value

10. All common attributes

Example:

<dropdown 
  field="class" 
  label="Character Class"
  options='[
    {"value": "fighter", "label": "Fighter"},
    {"value": "wizard", "label": "Wizard"},
    {"value": "rogue", "label": "Rogue"}
  ]'
  searchable="true"
></dropdown>

<dropdown 
  size='sm'
  field="effects"
  label="Effects"
  searchable='true' multiselect='10'
  description='Effects that this ability can apply'
  optionsquery='{"type": "effects", "query": {}}'
  placeholder='Select Effects...'>
</dropdown>

Progress Bar

Description: Adds a horizontal progress bar

Attributes:

1. field - The name for the field of the progress bar (not used for data)

2. currentvaluefield - The field for current value of the progress bar

3. maxvaluefield - Field containing the maximum value

4. maxvalue - Static maximum value, if maxvaluefield is not used

5. color - Can be set to 'health' to render the progress bar in different shades depending on the %-remaining

6. All common attributes

Example:

<progressbar 
  currentvaluefield="hp" 
  maxvaluefield="maxHp"
  label="Hit Points"
  color="health"
  radius="xl"
></progressbar>

Counter

Description: Adds a horizontal list of checkboxes for tracking counts.

Attributes:

1. field - The data field to store the count value

2. maxvalue - Static maximum value, used if maxvaluefield is not set

3. maxvaluefield - Field containing maximum value

4. All common attributes

<counter 
  field="hitDice" 
  label="Hit Dice"
  maxvaluefield="level"
></counter>

Button

Description: Displays a clickable button.

Attributes:

1. field - The data field to bind to. If the field contains a string, it will use this as the label for the button instead of the label property.

2. label - The label for the button if a string is not set in the field of the underlying data.

3. tooltip - A string value tooltip to render for the button. Expects an actual string, not a value containing underlying data.

4. icon - Icon to display on the button, if set

5. disablediflocked - If true, button is disabled when record is locked, if false it is enabled even when locked

6. All common attributes

7. Note: Buttons also support the custom sizes "xxs" and "xxxs"

Example:

<button 
  label="Roll Initiative"
  tooltip="Click to roll!"
  onclick="rollInitiative();"
  icon="dice"
  color="blue"
  variant="filled"
></button>

Icon Button

Description: Displays a button with different icon states. Can be used to toggle different states, or just have a button that is a singular icon.

Attributes:

1. field - The data field to bind the current value/state of the button to

2. disabled - Renders the icon button as a static non-clickable icon.

3. disablediflocked - If true, button is disabled when record is locked, if false it is enabled even when locked

4. options - Array of state options (as JSON string)

   1. Uses the JSON format [ {"value": "value", "label": "Label”, "icon": "IconName"} ]

5. getoptions - Function name to get options dynamically

6. All common attributes

Example:

<iconbutton 
  field="lightSource"
  options='[
    {"value": "off", "label": "Light Off", "icon": "IconBulbOff"},
    {"value": "dim", "label": "Dim Light", "icon": "IconBulb"},
    {"value": "bright", "label": "Bright Light", "icon": "IconBulb"}
  ]'
  onchange='onLightChange(value)'
></iconbutton>

Accordion

Description: Creates a collapsible section.

Attributes:

1. field - The data field to bind the collapsed state to, unless <accordion.control> is defined

2. icon - Icon to display on the header

3. listtype - Required type which determines how this list is rendered. Must match a List Type record defined in the Ruleset.

4. emptylisttext - Optional string of text to render when the list is empty. Overrides the text defined by the List Type record.

5. chevronposition - "left" or "right" (default "right"), defines where to render the chevron

6. All common attributes

Example:

<accordion label="Equipment" field="equipAcc">
  <div style="padding: 8px">
    <!-- Accordion content here -->
    <list field="equipment" listtype="item_list"></list>
  </div>
</accordion>

<accordion label="Equipment" field="equipAcc">
  <accordion.control> 
    <!-- Custom content here to render in the accordion instead -->
  </accordion.control> 
  <div style="padding: 8px">
    <!-- Accordion content here -->
    <list field="equipment" listtype="item_list"></list>
  </div>
</accordion>

Indicator

Description: Adds an indicator around another field.

Attributes:

1. field - The data field to display in the indicator

2. position - Position of the indicator

3. All common attributes

Example:

<indicator 
  field="concentration"
  position="top-right"
  color="yellow"
>
  <stringfield field="spell" label="Active Spell"></stringfield>
</indicator>

Popover

Description: Adds a popover panel that is triggered when clicking the element in the Target. The Panel appears above the Record with the given fields in the Dropdown. Requires a Target and Dropdown child tag (see example below.)

Attributes:

1. placement - The placement for the popover (top, left, right, bottom, top-start, top-end, etc.) Defaults bottom.

2. offset - Optional offset from the target to render. Expects a number.

3. radius - Optional radius of the popover.

4. width - Optional width for the popover panel.

5. height - Optional height for the popover panel.

6. onclose - Optional script to run when the popover is closed.

7. onopen - Optional script to run when the popover is closed.

Example:

<popover position="bottom" offset="4" witharrow="true" onopen="" onclose="">
  <popover.target>
    <button label="Open Popover" field="Open Popover"></button>
  </popover.target>
  <popover.dropdown>
    <numberfield field="exampleField" label="Example Field"></numberfield>
  </popover.dropdown>
</popover>

Image

Description: Adds a basic Image to the Record. You must have a source URL that you can provide first.

Attributes:

1. src - The url to the image to render

2. alt - The alt text for the image.

3. fit - Option fit attribute, e.g. cover, contain.

4. width - Optional width for the image

5. height - Optional height for the image

Example:

<img src="https://some-url-here.io/image.png" alt="img" fit="cover" width="100px" height="100px"></img>

Box

Description: Adds a div to the Record that allows for using the API to control visibility.

Attributes:

1. field - The field name for the box for hiding/unhiding.

2. width - Optional width for the box

3. height - Optional height for the box

4. size - Controls the padding if displayed as a card

5. radius - Controls the radius of the border if displayed as a card

6. variant - Optional. Use either “default” or “card” - Card variant has a border with padding

7. hidden - If hidden by default

8. scrollarea - The scrollarea attribute on Box components enables scrolling with values "true" (auto), "hover", or "scroll" for vertical-only scrollbars, or append -xy (e.g., "hover-xy") to enable both horizontal and vertical scrolling.

9. hideonlocked - If true, hidden when record is locked

10. hidewhenidentified - Controls visibility based on identification state, useful for fields that should not be visible to players when unidentified

11. hideforplayers - Controls the visibility for Players. If the user is a Player (not the GM) and this is set to “true” then it will be hidden to them. It can also accept a data path to a value for dynamically hiding/unhiding a control. For example, if this is set to “data.hideToPlayers” and that value on the record is “true”, then it will be hidden for them, and if it changes to false, it will be shown.

Example:

<box field="box2" variant='card' radius='md' size='sm' color='blue'>
  <div style='display: flex; flex-direction: column'>
    <div>A div in a card</div>
    <div>A 2nd div in a card</div>
  </div>
</box>

List

Description: Creates a list of sub-records of a specific type as described above.

Attributes:

1. field - The data field containing the list items

2. listtype - The record type to use for list items (must match the ‘type’ defined for the List Type)

3. allowadd - Function to call to determine if new items can be added — must return true or false and should be defined in the script section

4. getfilters - Function name to determine list filters programatically.

5. lazy - If this field is set to "true" elements of the list will only render once scrolled into view. This is strongly recommended for potentially long lists with complicated layouts, such as spells or abilities. Most lists will not need this, but enabling it will improve the initial load times of tabs that contain the list.

6. scroll - The Mantine scroll setting to use on the list area. Defaults to "scroll" (show scrollbars only on scroll) and also allows "hover", "auto", "always", or "never".

7. variant - Supports variants: “striped”, “outline”, “outline-striped” or any of the previous with “-flex” in the variant. A variant containing “flex” tells Single Row lists to stretch up or down to their item’s min/max length.

8. keepitemondrag - If "true" items will not be removed from the list when dragged to another list.

9. recordtype - Override the record type used when opening list items (e.g. open features as feats)

10. icon - Override the icon displayed for list items (e.g. icon="IconFlare")

11. All common attributes

Example of Get Filters:

  function getSpellFilters() {
    // If "Hide Unprepared Spells" is checked, filter out unprepared spells
    if (record?.data?.hideUnpreparedSpells) {
      return [{ field: 'prepared', operator: 'not_equals', value: 'unprepared' }];
    }
    return [];
  }

Example:

<list 
  field="inventory" 
  listtype="item"
  label="Inventory"
  allowadd="canAddItem()"
  height="400px"
  scroll="auto"
></list>

Record Select List

Description: Adds a searchable / filterable display of Records in the campaign so that you can built built in search lists to a specific record type, or wizard steps such as Character Wizards. The onChange handler will pass the selections, assuming selectable is true in the attributes as shown in the example below.

Note: The list will only show Shared records to Players.

Attributes:

1. filters - The filters to show, if any. Must be a JSON string as shown in the example below.

2. query - The query to use for searching on record types within the campaign. The “type” Must match a record type within the ruleset. See the example below.

3. All common attributes

Example:

<script>
 function onChange(value) {
   // Do something with values selected...
 }
</script>

<recordselectlist 
  width="100%" 
  height="350px"
  size="sm"
  field="recordselectlist"
  label="Select Items"
  onload="onLoad();"
  onchange="onChange(value);"
  query='{"type": "items", "query": {}}'
  filters='[{"label": "Type", "field": "type", "options": [{"label": "Weapon", "value": "weapon"}, {"label": "Gear", "value": "gear"}]}]'
  searchable="true"
  selectable="true">
</recordselectlist>

FXControl

Description: Adds a control panel to the Record that allows the user to set all fields pertaining to Animations and Sounds and stores the parameters in the given field name. These fields can be passed to api.playAnimation (see below in API section.)

Attributes:

1. field - The data field containing the list items

Example:

<fxcontrol field="animation"></fxcontrol>

Common Attributes

All components support these basic attributes:

1. field - Data field to bind to

2. label - Display label above the field, if supported by field type

3. height - Element height

4. width - Element width

5. description - Description text displayed under the label, if supported by field type

6. placeholder - Input placeholder text, if supported by field type

7. size - Element size (xs, sm, md, lg, xl)

8. color - Element color (uses Mantine color system)

9. variant - Visual variant — uses Mantine variants, with some modifications for certain fields (unstyled, outline, filled, striped, outline-striped)

10. onclick - Click event handler function name, should be a function either in the Common Script or in the Record’s script

11. onload - Load event handler function name, should be a function either in the Common Script or in the Record’s script

12. onchange - Change event handler function name, should be a function either in the Common Script or in the Record’s script, called ONLY on the machine of the User that changes the value, NOT when changed by another user or process

13. hidden - If true, element is hidden by default — see the API section for hiding and unhiding fields

14. radius - Border radius (xs, sm, md, lg, xl)

15. textalign - Text alignment (left, center, right)

16. hideonlocked - If true, hidden when record is locked, if false, hidden when the record is unlocked.

17. hidewhenidentified - Controls visibility based on identification state, useful for fields that should not be visible to players when unidentified

18. hideforplayers - Controls the visibility for Players. If the user is a Player (not the GM) and this is set to “true” then it will be hidden to them. It can also accept a data path to a value for dynamically hiding/unhiding a control. For example, if this is set to “data.hideToPlayers” and that value on the record is “true”, then it will be hidden for them, and if it changes to false, it will be shown.

Attribute Field

Description: A composite field for ability scores and attributes. Combines a number input, modifier badge, and optional action button into a single configurable component. Supports container variants with ornate borders and legend-style labels.

Attributes:

field - The data field to store the score value (e.g. strength or abilities.strength.score)

modifierfield - Data field for the modifier value (e.g. strengthMod). If set, displays a modifier badge.

modifierposition - Position of the modifier badge: bottom-center (default), bottom-start, bottom-end, top-center, top-start, top-end

modifiereditable - If "true", the modifier badge becomes an editable input

modifierdefaultvalue - Default display when modifier has no value (default: +0)

modifiershowsign - If "true" (default), shows + prefix on positive modifiers. Set to "false" to hide the sign.

showsign - If "true", always shows + or - sign on the score value

showbutton - If present, shows an action button alongside the score

buttonicon - Icon name for the button (renders as an ActionIcon, e.g. d20, IconSword)

buttontext - Text label for the button (renders as a standard Button). buttonicon takes precedence if both are set.

buttonposition - Placement of the button: right (default), left, top, bottom

buttonvariant - Mantine variant for the button (e.g. light, filled, outline, default)

buttoncolor - Color for the button

buttonsize - Size of the button (default: xl)

containervariant - Container style: bordered (simple border), fancy (metallic gradient border with glow). When set, the label renders as a legend on the top border and the modifier centers on the container. The width attribute controls the container width.

showcontrols - If "true", shows the NumberInput up/down spinner controls (default: false)

updateonblur - If "true", only updates the value when the field loses focus instead of on every keystroke

textalign - Text alignment for the label and input (e.g. center, left, right)

editable - If "true", the score is always editable even if the record is locked. If "false", it is always disabled.

bold - If "true", shows both the label and score value in bold font

defaultvalue - Default value if none is set

All common attributes (label, size, width, height, color, variant, radius, placeholder, hidden, hideonlocked, hidewhenidentified, hideforplayers, onclick, onchange, onload)

Examples:

Basic attribute with modifier and roll button:

<attribute
  field="strength"
  modifierfield="strengthMod"
  label="STR"
  showbutton
  buttonicon="d20"
  onclick="rollCheck('strength')"
  onchange="onAbilityScoreChanged(value, 'strength')"
></attribute>

Fancy bordered attribute with centered text:

<attribute
  field="strength"
  modifierfield="strengthMod"
  label="STR"
  size="sm"
  width="130px"
  containervariant="fancy"
  textalign="center"
  bold="true"
  showbutton
  buttonicon="d20"
  buttonsize="lg"
  buttonvariant="light"
  onclick="rollCheck('strength')"
  onchange="setModifier(value, 'strength')"
></attribute>

Simple attribute without button or modifier:

<attribute
  field="level"
  label="Level"
  size="sm"
  width="80px"
  textalign="center"
  containervariant="bordered"
></attribute>

Attribute with text button and editable modifier:

<attribute
  field="charisma"
  modifierfield="charismaMod"
  modifiereditable="true"
  label="CHA"
  showbutton
  buttontext="Roll"
  buttonposition="bottom"
></attribute>

JavaScript API

The Realm VTT API provides a comprehensive set of tools for interacting with the virtual tabletop environment. This API is available within scripts and macros, allowing for complex automation and game management.

The following section describes all the functions and data available in the JavaScript executed by the VTT.

These values and the functions provided in api can be used in the Script section of a Record, List, or anywhere a Script is defined in the Settings tab.

Additionally, some of this information is provided in the auto complete functions of the Code Editors within the Ruleset Editor.

Context

Scripts are run in a particular context (usually a Record, a Roll Handler, a Combat Tracker Script, a Token Context Script, or a Party Sheet Script).

Scripts have access to several context variables:

1. value - The current field's value

2. dataPath - Path to the field's data in the parent record

3. record - The current record or list item

4. isGM - Boolean indicating if user is GM

5. userId - Current user's ID

6. recordType - Type of current record

7. data - Additional contextual data

   1. data.token: object | null

      1. [Combat Tracker Scripts] The currently active token in combat.

   2. data.tokens: Array<object>

      1. [Combat Tracker Scripts] All tokens currently in the combat tracker.

   3. data.initiative: number

      1. [Combat Tracker Scripts] The current initiative count in combat.

   4. data.round: number

      1. [Combat Tracker Scripts] The current round count in combat.

   5. data.roll: object

      1. [Roll Handler Scripts] The result of a dice roll, containing total, dice results, and metadata.

   6. data.character: object | null

      1. [Macros] The most recent character created by the player in the campaign.

Available API Calls

Getting Records

• getRecord(recordType: string, recordId: string, callback: (record: object) => void)

You can fetch any record in the currrent campaign using getRecord.

// Fetch a character record
api.getRecord("characters", "id-here", (character) => {
  console.log(character.name);
});

• getRecordByTypeAndName(recordType: string, name: string, callback: (record: object) => void)

You can fetch any record by the exact name using getRecordByTypeAndName. Note: this will return the first Record found, so this is only ideal when searching for a very specific known record such as a Skill, Spell, etc. If there are duplicates, it returns the first one found.

// Fetch a skill record
api.getRecord("skill", "Athletics", (skill) => {
  console.log(skill);
});

• getRecordsByQuery(recordType: string, query: object, callback: (records: object[]) => void, limit?: number)

Query records in the current campaign by type with additional filters. Returns an array of matching records, up to 50 by default. You can pass any data path as a query filter.

// Find all Cantrip spells
api.getRecordsByQuery('records', { 'data.recordType': 'spells', 'data.level': 'Cantrip' }, (spells) => {
  console.log('Found', spells.length, 'cantrips');
  spells.forEach(spell => console.log(spell.name));
});

// Find records by a specific slug
api.getRecordsByQuery('records', { 'data.slug': 'fire-magic' }, (records) => {
  console.log(records);
});

// Limit results to 10
api.getRecordsByQuery('records', { 'data.type': 'weapon' }, (weapons) => {
  console.log('First 10 weapons:', weapons);
}, 10);

• openRecord(record: object)

This will open the window for a record that has been fetched from one of the above API calls, meant to be used within the callback function of one of the above.

// Open a record's window
api.openRecord(record);

Setting Record Links

• setRecordLink(path: string, recordLink: {value: object, tooltip: string, type: string}, callback?: (record) => void)

Record links are set on Record Link fields using setRecordLink.

api.setRecordLink("equipment.mainHand", {
  value: weaponRecord,
  tooltip: "Longsword",
  type: "weapons"
}, (updatedRecord) => {
  console.log("Weapon equipped");
});

Effect Management

For detailed information on how to leverage complex effects, see the Effects System documentation at the end of this article.

• addEffect(effectName: string, actorToken: object, effectDurationSeconds?: number, effectValue?: string | token, callback?: (record) => void)

Adds an effect to a token by Effect Name. The Effect must be in the campaign. Effect value can be used to store information such as who applied the effect (if a token is provided.)

• addEffects(effectNames: [string], actorToken: object, effectDurationSeconds?: number, effectValue?: string | token, callback?: (record) => void)

Adds an array of effects to a token by Effect Names. The Effects must be in the campaign. Duplicate effects will only be applied if they are stackable (i.e. ['Stunned', 'Stunned'] apples Stunned 2, if the Stunned effect can be stacked.)

• addEffectById(effectId: string, actorToken: object, effectDurationSeconds?: number, effectValue?: string | token, callback?: (record) => void)

Adds an effect to a token by Effect ID. The Effect must be in the campaign.

• addEffectsByIds(effectIds: [string] actorToken: object, effectDurationSeconds?: number, effectValue?: string | token, callback?: (record) => void)

Adds an array of effects to a token by Effect IDs. The Effects must be in the campaign. Duplicate effects will only be applied if they are stackable.

• addTokenChangeEffect(npcId: string, actorToken: object, callback?: (record) => void)

Adds an Effect to the actor token that changes their Token to match the token image and size of the given NPC, by ID. That NPC must be in the campaign.

• removeEffectById(effectId: string, actorToken: object, callback?: (record) => void)

Removes the Effect by the given Effect ID on the token.

• deductEffectById(effectId: string, actorToken: object, callback?: (record) => void)

Deducts the Effect by 1, if it was a stacked effect. Removes the given Effect ID on the token if it was the last instance or was not a stacked effect.

// Add a "Poisoned" effect for 60 seconds
api.addEffect("Poisoned", targetToken, 60, customV);

// Add effect by ID with a custom value
api.addEffectById("effect-id-1", targetToken, undefined, "Concetration on Bless");

// Change token appearance
api.addTokenChangeEffect("npc-wolf-id", characterToken);

Value Management

• getValue(path: string): any

Gets a value from the current record's context data by dataPath.

This could also be a path to a List value, see example below.

const hp = api.getValue("data.hpCurrent");

const item2 = api.getValue("data.items.1");

• getValueOnRecord(record: object, path: string): any

Gets a value from the given record's context data by dataPath. Similar to the object, but with a required record field.

• setValue(dataPath: string, newValue: any, callback?: (record) => void)

Sets a value in the current record's data.

api.setValue("data.hp", hp - 5, (updatedRecord) => {
  console.log("HP updated");
});

• setValues(dataPathValues: {[path: string]: any}, callback?: (record) => void)

Sets multiple values at once in the current record's data. This is recommending when changing many values in an onchange handler, such as when updating a Character’s attribute. For performance reasons, you should always use setValues when affecting more than one value on a Record.

You can even use this to unhide/hide values using the fields metadata object. See example below:

api.setValues({
  "data.hpCurrent": hp - 5,
  "data.wounded": true,
  "fields.woundedLabel.hidden": false,
  "fields.healthyLabel.hidden": true
}, (updatedRecord) => {
  console.log("Values updated");
});

• setValuesOnRecord(record: object, dataPathValues: {[path: string]: any}, callback?: (record) => void)

Sets multiple values at once on the given Record. This is recommending when changing values in a callback on another reocord, or in roll handlers after re-querying the record.

api.setValuesOnRecord(record, {
  "data.hpCurrent": hp - 5,
  "data.wounded": true,
  "fields.woundedLabel.hidden": false,
  "fields.healthyLabel.hidden": true
}, (updatedRecord) => {
  console.log("Values updated");
});

• addValue(path: string, newValue: object, callback?: (record) => void)

Adds a single value to a list field at the specified path. The element will automatically be assigned a unique ID.

api.addValue("data.inventory", {
    name: "Health Potion",
    data: {
      quantity: 1,
      weight: 0.5
    }
}, (updatedRecord) => {
    console.log("Item added to inventory");
});

• addValues(path: string, values: Array<object>, callback?: (record) => void)

Adds multiple values to a list field at the specified path. Each value will automatically be assigned a unique ID.

// Add multiple items to inventory at once
api.addValues("data.inventory", [
    {
        name: "Sword",
        data: {
          damage: "1d8",
          weight: 3
        }
    },
    {
        name: "Shield",
        data: {
          armorClass: 2,
          weight: 6
        }
    }
], (updatedRecord) => {
    console.log("Items added to inventory");
});

• addValuesOnRecord(record: object, path: string, values: Array<object>, callback?: (record) => void)

Much like addValues but on the passed record instead of the context’s record.

• removeValue(path: string, index: number, callback?: (record) => void)

Removes a value from a list field at the specified path and index.

api.removeValue("data.inventory", 1, (updatedRecord) => {
    console.log("Second item removed from inventory");
});

• removeValueFromRecord(record: object, path: string, index: number, callback?: (record) => void)

Removes a value from a list field at the specified path and index on a specific record instead of the context’s record.

• setValueOnToken(token: object, relativePath: string, newValue: any, callback?: (record) => void)

Sets a value on a specific token using a relative path. This is useful when you need to modify a different token's data directly (and not the current record context).

api.setValueOnToken(token, "data.hpCurrent", 50, (updatedRecord) => {
  console.log("Token HP updated");
});

• setValueOnTokenById(tokenId: string, recordType: string, relativePath: string, newValue: any, callback?: (record) => void)

Sets a value on a token using its ID and record type. This is useful when you only have a token's ID and need to modify its data.

api.setValueOnToken(token._id, "npcs", "data.hpCurrent", 50, (updatedRecord) => {
  console.log("Token HP updated");
});

• setValuesOnTokenById(tokenId: string, recordType: string, dataPathValues: {[path: string]: any}, callback?: (record) => void)

Similar to setValuesOnRecord but requires a token ID and a recordType. Useful when setting many values on a particular token and you only want to pass the ID of the token.

api.setValuesOnTokenById(token._id, "characters", {
  "data.hpCurrent": hp - 5,
  "data.wounded": true,
  "fields.woundedLabel.hidden": false,
  "fields.healthyLabel.hidden": true
}, (updatedRecord) => {
  console.log("Values updated");
});

Dice Rolls

• roll(roll: string, metadata?: object, rollType: string = "chat")

Performs a roll without prompting. The roll type defaults to “chat” but otherwise, it should match a Roll Type as defined in the Settings tab. (See the section later on Roll Handlers.)

api.roll("2d20dl1 + 5", { rollName: "Attack Roll" }, "attack");

• rollInstant(roll: string): {total: number, results: Array<{type: number, value: number}>, modifier: number}

Performs an immediate roll and returns the result without any animation in the VTT.

const result = api.rollInstant("1d20");
console.log(`Rolled a ${result.total}`);

• promptRoll(name: string, roll: string, modifiers: Array<{name: string, type: string, value: any, active: boolean}>, metadata?: object, rollType: string = "chat")

Prompts for a roll with modifiers and passes along the given metadata to the roll handler. The roll type defaults to “chat” but otherwise, it should match a Roll Type as defined in the Settings tab. (See the section later on Roll Handlers.)

This is the primary method that should be used for most rolls, so that Players have more control over the modifiers that are passed along and can toggle or add more the roll beforehand.

Note: Metadata should be relatively light. Do not add entire Records or Tokens to Metadata as this may cause performance issues later if the Records are very large. Pass IDs instead and use the getRecord API call in the Handlers.

api.promptRoll(
  "Fire Sword",
  "1d6 piercing + 1 piercing",
  [
    { name: "Fire Enchantment", type: "fire", value: "1d4 fire", active: true }
  ],
  { "isAttack": true },
  "damage"
);

• promptRollForToken(tokenForRoll: object, name: string, roll: string, modifiers: Array<object>, metadata?: object, rollType: string = "chat")

When called, opens a Roll Prompt using the given token as the actor making the roll. Used when needing to make rolls as a specific token rather than the selected one.

const selectedTokens = api.getSelectedOrDroppedToken();
selectedTokens.forEach(token => {
  const tokenDexMod = token.data.dexMod || 0;
  api.promptRollForToken(
    token,
    "Dexterity Save",
    "1d20",
    [{
      name: "Dex Mod",
      type: "",
      value: tokenDexMod
    }],
    { saveDC: 15 },
    "save"
  );
});

• rollOnTable(tableId: string)

Rolls on a table by its ID. This triggers the full table roll flow — dice are rolled using the table's die formula, the matching result row is posted to chat, and any subtable links in the result are automatically rolled on as well.

api.rollOnTable("60f7b2a1c9e77c001f8a1234");

• rollOnTableByName(tableName: string)

Rolls on a table by its name in the current campaign. Works identically to rollOnTable but looks the table up by name instead of ID. If the table is not found, a notification is shown suggesting the module containing it may need to be imported.

api.rollOnTableByName("Wild Magic Surge");

• getTableResult(tableId: string, rollTotal: number, callback: function)

Gets the matching result row for a table by ID and a given roll total, without triggering a dice roll or posting to chat. Useful when you want to roll on a table programmatically and process the result yourself (e.g., applying effects based on the result). The callback receives (results, table) where results is an array of column objects with text and optional recordLink properties.

let roll = api.rollInstant("1d100");
api.getTableResult("60f7b2a1c9e77c001f8a1234", roll.total, (results, table) => {
  if (results && results.length > 0) {
    api.sendMessage(`**${table.name}:** ${results[0].text}`);
  }
});

• getTableResultByName(tableName: string, rollTotal: number, callback: function)

Gets the matching result row for a table by name and a given roll total, without triggering a dice roll or posting to chat. Works identically to getTableResult but looks the table up by name instead of ID. If the table is not found, a notification is shown suggesting the module containing it may need to be imported.

let roll = api.rollInstant("1d20");
api.getTableResultByName("Random Encounters", roll.total, (results, table) => {
  if (results && results.length > 0) {
    api.sendMessage(`**${table.name}:** ${results[0].text}`);
  }
});

Token Management

• getSelectedTokens(): Array<object>

Returns all selected tokens on the scene.

const tokens = api.getSelectedTokens();

• getTargets(): Array<object>

Gets all targeted tokens and their distances to the token corresponding to the current record context.

const targets = api.getTargets();
targets.forEach((target) => {
  const targetToken = target.token;
  const targetDistance = target.distance || 0;
});
  

• getSelectedOwnedTokens(): Array<object>

Returns an array of tokens that are both selected and owned by the current player. If no owned tokens are selected, returns an array containing just the player's default token (if any). This is particularly useful for player scripts where you want to ensure they can only affect tokens they own.

// Get all tokens the player owns and has selected
const ownedTokens = api.getSelectedOwnedTokens();

• getDistance(token1: object, token2: object): number

Gets the distance between two tokens.

const distance = api.getDistance(tokenA, tokenB);

• getToken(): object | null

Returns the current token based on context. Priority order:

1. Token from data context

2. For GMs: First selected token

3. For Players: Player's token

4. Token associated with current record

// Get the contextually relevant token
const token = api.getToken();
if (token) {
    console.log("Found token:", token.name);
}

• getOtherTokens(): Array<object>

Returns all tokens on the current scene except for the contextual token (from getToken()).

// Get all other tokens on the scene
const otherTokens = api.getOtherTokens();
console.log(`There are ${otherTokens.length} other tokens on the scene`);

// Example: Find nearest token
const nearestToken = otherTokens.reduce((nearest, current) => {
    const currentDistance = api.getDistance(api.getToken(), current);
    const nearestDistance = nearest ? api.getDistance(api.getToken(), nearest) : Infinity;
    return currentDistance < nearestDistance ? current : nearest;
}, null);

• getSelectedOrDroppedToken(): Array<object>

Returns an array of tokens based on the current context. The method follows this priority:

1. If the macro was dropped on a token, returns an array containing just that token

2. If tokens are selected, returns array of selected tokens

3. If user is not a GM and has a character, returns array containing their character

4. Otherwise, returns empty array

const tokens = api.getSelectedOrDroppedToken();

• isOwner(token: object): boolean

Determines if the current user owns the specified token. Returns true if the user is a GM or if they are the owner of the token.

// Check if current user owns a token
const token = api.getToken();
if (api.isOwner(token)) {
    console.log("User can control this token");
} else {
    console.log("User cannot control this token");
}

Chat & Notifications

• sendMessage(message: string, roll?: object, recordLinks?: Array<object>, tags?: Array<string>, asToken?: object)

Sends a chat message. Record Links are added to the bottom of the message, if provided. Tags are rendered at the top of the message, if provided.

Messages support Markdown using the following:

1. bold → bold

2. italic → italic

3. ***bold italic*** → bold italic

4. strikethrough → strikethrough

5. # Header 1

   ## Header 2

   ### Header 3

   #### Header 4

   ##### Header 5

   ###### Header 6

6. Tables
   | Header 1 | Header 2 |

   |----------|----------|

   | Cell 1 | Cell 2 |

   | Cell 3 | Cell 4 |

7. Lists
   - Unordered list item

   * Also unordered

   1. Ordered list item

   2. Second ordered item

8. Macros
   ```MacroNameSeparatedByUnderscores

   Code to Execute on Click
   ```

9. Custom Tags

   1. :iconname: → Displays icon from system

   2. [tagname|tooltip] → Displays tag with hover tooltip

   3. [color=red]Colored text[/color] → Colored text

   4. [center]Centered text[/center] → Centered text

   5. [gm]Only GMs can see this[/gm` → Text only visible to GMs

// Basic message
const tags = [
  {
    tooltip: "Basic Attack",
    name: "Attack",
  }
]
api.sendMessage(`Attack Result: ${someValue}`, undefined, tags);

// Send a message as a specific token (GM only)
api.sendMessage("*growls*", null, [], [], tokenObject);

Macros within messages can become pretty complex considering they must be placed within backticks (`). Here is an example:

const damageButton = `\`\`\`Roll_Damage
api.promptRoll(\`${spellName} Damage\`, '${spellDamage}', ${JSON.stringify(damageModifiers
)}, ${JSON.stringify(saveDamageMetadata)}, 'damage')
\`\`\``;

const message = `
  ${damageButton}
`

api.sendMessage(message);

• editMessage(messageId: string | null, message: string, callback?: () => void)

Edits an existing chat message. For more examples, you can see the “damage” roll handler in Realm VTT Basic or D&D 5e for how it gets the message ID and edits messages.

api.editMessage("message-id-123", "Updated text");

• showNotification(message: string, color?: string, title?: string)

Shows a notification to the user.

api.showNotification(
  "Target is too far away!",
  "red",
  "Range Error"
);

Utility Functions

• showPrompt(name: string, label: string, text: string, options: Array<{label: string, value: any}> | null, optionsQuery: {type: string, query: object} | null, callback?: (selection: any) => void, okButtonText: string = "OK", cancelButtonText: string = "Cancel", maxOptions: number = 1)

Shows a selection prompt to the user. Can be a defined set of options, or a query to get data from the current campaign. Used for when prompting to make selections such as during a Level Up.

api.showPrompt(
  "Choose Weapon",
  "Select weapon to start with",
  "Choose carefully",
  [
    { label: "Sword", value: "sword" },
    { label: "Bow", value: "bow" }
  ],
  null,
  (selection) => console.log(selection),
  "Select",
  "Cancel",
  1 // Only allow 1 option
);

// Another example, note that chaining prompts should be done 
// using the callbacks
api.showPrompt(
  `Choose 2 Skills`,
  "Skills",
  "Select 2 General Skills...",
  null,
  {
    type: "skills",
    query: {
      "data.type": "general",
    },
  },
  skillSelectionCallback,
  "OK",
  "Cancel",
  2
);

• showConfirm(title [optional, defaults to 'Confirm'], text [optional, defaults to 'Are you sure?'], confirmLabel [optional, defaults to 'Confirm'], cancelLabel [optional, defaults to 'Cancel'], onConfirm)

Shows a confirmation prompt to the user for simple Yes/No responses.

function onConfirm() {
  console.log("You hit OK.");
}

api.showConfirm("Confirm", "You sure?", "OK", "Cancel", onConfirm);

• showValuePrompt(name: string, label: string, label: string, callback?: (selection: any) => void, okButtonText: string = "OK", cancelButtonText: string = "Cancel")

Show a text input prompt to the user. Supports flexible parameters: (name, label, callback) for simple use, or (name, label, text, callback, okButtonText, cancelButtonText) for full control. The callback receives the entered value or null if cancelled.

api.showValuePrompt(
  "Enter Deity",
  "What god do you worship?",
  (selection) => console.log(selection),
  "Enter",
  "Cancel"
);

• richTextToMarkdown(html: string): string

Converts HTML to markdown. Useful for converting descriptions from Rich Text fields to a Chat Message.

const markdown = api.richTextToMarkdown("<strong>Bold</strong>");

• getSetting(key: string): string

Gets a campaign setting value. The key must be a setting as defined in the Ruleset Settings tab.

const includeCoinage = api.getSetting("coinWeight") === "yes";

• awardExp(amount: number, reason: string): void

Awards experience points to the party. Only works if called by a GM and if the Awards tab is enabled in the Party Sheet. Typically used in a Macro sent in a message by the Combat Tracker’s onEncounterEnd handler.

// Award XP to the party
if (isGM) {
    api.awardExp(100, "Defeated the dragon");
}

• dealFromDeck(deckName: string, tokenId: string, itemId: string, removeFromDeck: boolean, shuffleOnEmpty: boolean, callback: function): void

Looks up a Deck within the current campaign with the given name, then deals an item from the deck to the given tokenId. A tokenId of “all” deals the item to be visible to all players. A tokenId of “gm” deals it just the GM. Otherwise, it must be an ID of a Token on the Combat Tracker.

Provide an itemId to deal a specific Item from the Deck (by ID) or leave it as an empty string to deal the first item in the deck (after shuffling.) If removeFromDeck is true, the item is removed, else it is left in the Deck for others to get the same item (useful for Token packs.) If shuffleOnEmpty is true, the deck will be reshuffled once the last card is dealt, otherwise, it will error if empty.

The callback function is called with the item that was dealt as the only parameter.

const callback = (item) => {
	console.log('Drew: ' + item.value);
};
api.dealFromDeck('Test Deck', 'all', '', true, true, callback);

• shuffleDeck(deckName: string, useDiscardPile: boolean, callback: function): void

Looks up a Deck within the current campaign with the given name, then shuffles the Deck if found. If useDiscardPile is true, only the cards in the discard pile (if any) are shuffled back into the deck order, and the current dealt cards are left the same. Otherwise, all cards are dealt back to the deck.

The callback function is called with the deck that was shuffled as the only parameter.

const callback = (item) => {
	console.log('Shuffled: ', item);
};
api.shuffleDeck('Test Deck', false, callback);

• floatText(token: tokenObject, text: string, color: string) void

Floats text above the given token object on the current Scene.

const token = api.getOtherTokens()[0];
// Floats red -5 above first token found
api.floatText(token, "-5", "#FF0000")

• playAnimation(animation: object, originTokenId: string?, destinationTokenId: string?) Promise

Plays an animation on the current Scene. The animation can be static, move between tokens, or stretch between tokens. Returns a Promise that resolves when the animation completes.

The animationName must be a known animation in the system. Use the FXControl field on a record to allow users to pick from animations and get the valid parameters below.

Parameters:

• animation: Object of type described below - stored as a field by the FXControl (required)

• originTokenId: ID of Token on the scene to start animation from (optional, auto-detected if not provided,)

• destinationTokenId: ID of Token on the scene to animate towards (optional)

Animation Parameters:

• animationName: Name of the animation (e.g., "slash_1", "bolt_1")

• moveToDestination: Whether animation moves to destination

• stretchToDestination: Whether animation stretches to destination

• destinationOnly: Whether to play only at destination

• startAtCenter: If true, the animation starts from the origin token’s center

• scale: Scale multiplier (default from animation definition)

• opacity: Transparency 0-1 (default from animation definition)

• animationSpeed: Frame rate (default from animation definition)

• rotation: Additional rotation in degrees (default from animation definition)

• hue: Color hue 0-360 degrees (default from animation definition)

• contrast: Color saturation 0-1 (default from animation definition)

• brightness: Color brightness 0-1 (default from animation definition)

• moveSpeed: Movement speed in pixels/millisecond (default from animation definition)

• sound: Plays the sound effect by name (if it exists in Realm VTT) when the animation is played

• count: Number of times to fire off this animation successively (default 1)

// Simple slash animation at current token
api.playAnimation("slash_1");

// Lightning bolt that moves to target
const targets = api.getTargets();
if (targets.length > 0) {
  api.playAnimation("bolt_1", {
    destinationToken: targets[0].token,
    moveToDestination: true,
    hue: 240, // Blue lightning
    scale: 1.2
  });
}

// Beam that stretches between caster and target
const selectedTokens = api.getSelectedTokens();
const otherTokens = api.getOtherTokens();
if (selectedTokens.length > 0 && otherTokens.length > 0) {
  api.playAnimation("bolt_1", {
    originToken: selectedTokens[0].token,
    destinationToken: otherTokens[0],
    stretchToDestination: true,
    hue: 0, // Red beam
    opacity: 0.8
  });
}

// Animation only at destination
api.playAnimation("slash_1", {
  destinationToken: targets[0].token,
  destinationOnly: true,
  rotation: 45
});

• getParty(callback: function)

Gets a list of all characters in the current Party Sheet and returns it to the callback.

Parameters:

• callback: Calls the callback with the list of characters (objects).

function healParty(party) {
  party.forEach(character => {
    api.setValuesOnRecord(character, {
      ['data.curhp']: character.data?.hitpoints
    });
  });
  api.sendMessage(`Healed ${party.length} Characters`)
}

api.getParty(healParty);

• removePartySheetItem(itemId: string, callback: function)

Remove an item from the party sheet by ID. GM only. Parameters: (itemId, callback). The itemId is usually obtained from a callback or an onDrop.

Parameters:

• callback: Calls the callback with the new party sheet (object).

api.removePartySheetItem("some-id-here", () => {
  console.log("Done!");
});

• addPartySheetItem(record: object, quantity: number, callback: function)

Adds an item from the party sheet. GM only. Parameters: (itemId, callback). The item is usually received from a callback or an onDrop handler.

Parameters:

• callback: Calls the callback with the new party sheet (object).

api.addPartySheetItem(itemObject, () => {
  console.log("Done!");
});

• getCombatTracker(callback: function)

Gets the Combat Tracker data and calls the callback with an object containing the round, initiative, and tokenIds.

Parameters:

• callback: Calls the callback with the list of characters (objects).

api.getCombatTracker((ct) => {
  console.log(`Current initiative is ${ct.initiative}`);
});

• delay(callback: function, time: number)

A replacement for the "setTimeout" function. Calls the callback after the number of milliseconds provided by "time" to a max of 5000.

Parameters:

• callback: Calls the callback

• time: Milliseconds to wait

api.delay(() => {
  console.log(`Waited 500 ms!`);
}, 500);

• getCampaign(): { rulesetId, rulesetName, rulesetVersion, name }

Returns information about the current campaign and its ruleset.

const campaign = api.getCampaign();
console.log(campaign.name); // "My Campaign"
console.log(campaign.rulesetName); // "Dungeons and Dragons 5th Edition (2024)"
console.log(campaign.rulesetVersion); // 1
console.log(campaign.rulesetId); // "some-id-here"

Ruleset Settings

The Settings Tab of the Ruleset gives you additional controls over how the Ruleset functions within the VTT.

Token Health

From this Section you can define which fields are used in an NPC and Characters record for the max health and current health of the token (stored in data.(fieldName).

You can also disable health indicators in the ruleset by clicking the checkbox “Disable Health Indicators.”

If both fields are defined and set properly, you can also define what the color of the health bars on the tokens should be for a given percentage remaining.

The label defined for each is the “Health Status” that is shown to players. Players do not see the Health Bars of enemy faction tokens, but will see it for Friendly tokens.

Damage & Healing

The Damage & Healing settings controls the ability to set damage or healing on a Token via the Token Context Menu (right clicking a Token) in the VTT. If enabled, the fields will show up. The scripts defined in each Accordion (Damage Script / Healing Script) are executed when a value is set. These scripts must be written per the definition of your Characters and NPCs. Note that the Health fields must be the same on both Characters and NPCs.

These scripts execute with record set as the token selected and value set as the value entered.

Here is an example:

// Apply healing
// Ignore negative healing as that is what damage is for
// This script ignores tempHp, as it is not a factor in healing
if (value > 0) {
  var curhp = record.data?.curhp || 0;
  curhp += value;
  if (curhp < 0) { curhp = 0; }
  if (curhp > record.data?.hitpoints) { curhp = record.data?.hitpoints; }
  api.setValue("data.curhp", curhp);
}

The Damage Type Icons accordion can be expanded to define custom icons for specific damage type that are used in the scripts of your Ruleset.

Icons must be either a Tabler Icon, a Game Icon or one of the following:

• icon-acid

• icon-bleed

• icon-bludgeoning

• icon-cold

• icon-fire

• icon-force

• icon-lightning

• icon-necrotic

• icon-piercing

• icon-poison

• icon-mental

• icon-radiant

• icon-slashing

• icon-sonic

• icon-unholy

• icon-spirit

• icon-vitality

• icon-void

• icon-holy

• icon-explosive

• icon-handgun

• icon-rifle

• icon-grenade

• icon-magic

• icon-healing

• icon-precision

Token Size Options

From this section, you can define what Size tokens are rendered at by the data.size field on the NPC or Character.

Note: To use this function your NPCs and Characters should define a size string field on the record that is editable.

Combat Tracker

In the Combat Tracker settings you can define the value used on NPCs and Character’s for storing initiative (and rendered in the Combat Tracker) as well as whether it is descending or ascending order.

The Additional Fields accordion allows you to define additional fields that you want to render in the Combat Tracker.

• Note: The fields should all be defined on both NPCs and Characters otherwise they will be empty for one or the other

The following Event Types are editable in a different script handler here, and are called at various times when the Combat Tracker is used. The Context is set per the Data above in the API section.

These scripts are only executed by the GM.

• On Token Add

  • When a token is added to the Combat Tracker, this script is called.

• On Encounter Start

  • When clicking Start Encounter, this script is called.

• On Encounter End

  • When clicking End Encounter, this script is called.

• On Turn Start

  • When clicking the Next Turn button, this script is called with the data.token set to the one who’s turn is starting.

• On Turn End

  • When clicking the Next Turn button, this script is called with the data.token set to the one who’s turn is ending.

• On Round Start

  • When clicking Next Turn (if a new round is starting) or when clicking Next Round, this script is called

• On Round End

  • When clicking Next Turn (if a new round is starting) or when clicking Next Round, this script is called

• On Roll Initiative

  • This script is called when the Combat Tracker “Roll Initiative” button is pressed and should define how to prompt for an initiative roll for the context’s token in data.token

• On Roll Initative (Group)

  • This optional script is called when the Combat Tracker “Roll Initiative for Each NPC Group” button is pressed and should define how to prompt for an initiative roll for each unique NPC

Party Sheet

Additional Party Fields

From the Party Sheet settings you can define all the fields that are shown on each entry in the Party Sheet. The GM can add Characters to the Party Sheet. Each field defined here will show up on each entry.

Inventory Tab Settings

You can enable or disable the Inventory Tab here as well as define fields that show up for each element in the Inventory tab of the Party Sheet.

Awards Tab Settings

In the Awards Tab you can define if XP can be awarded and if so what the default method is and what the name of the field is to store XP on each Character Sheet.

You can also define a list of Currencies that will then show up in the Party Sheet and allow the GM to distribute currency to Characters in the Party.

Misc

The Party Sheet also has hooks into Encounters. For example, if there are 2 PCs in the Party Sheet and the GM has an encounter with Goblins in it, he can set the number of the Goblins in the encounter to “$PC” and it will add 2 Goblins to the Combat Tracker.

Calendars

In the Calendars setting you can define Calendars that are available in the Ruleset.

By default, all Rulesets can use the Gregorian calendar.

Effects

From the Effects settings we define the list of additional Rule Types that can be selected when creating Effects in the Campaign.

These Rule Types do nothing on their own, they simple provide a way for GMs and Players to add them to an Effect so that they can then be used by the scripts in the Ruleset.

The Roll Handlers and Macros throughout the ruleset should check for these Effects on tokens and add modifiers as necessary to roll prompts. You can check out the D&D 5e (2024) ruleset for a comprehensive example of how this works.

We also suggest using the Common Script in Additional Settings to define your function for gathering all the Effects (and any modifiers from token values such as equipped items, etc.) that you can then re-use and call everywhere in your ruleset code for automation of these effects.

Roll Handlers

The Roll Handlers section should define a Roll Handler for every type used within your scripts. For example, if you prompt a roll in a script of type “attack” you should define a Roll Handler here called “attack” and then enter the script.

The script is called by the User who performed the Roll, so keep that in mind when writing the code. If you do not want Users to edit a token directly (for example when dealing damage) then you should have the Roll Handler output a message with a macro that the GM can use to apply damage. The D&D 5e (2024) ruleset is a good starting place to see how it is implemented there.

Metadata that was passed along to a Roll is provided here in the handler via data.roll.metadata

Campaign Settings

The Campaign Settings section lets you define additional settings that the GM can set for their campaign. These settings do nothing on their own, you should use the api.getSetting call to check the value of a setting in all relevant scripts.

Additional Settings

Finally, the Additional Settings section has some miscellaneous settings for the Ruleset.

• Show Advantage / Disadvantage Buttons in Roll Prompt

  • If your ruleset has the ability to roll with some type of “advantage” (i.e. 2d20 drop lowest) or “disadvantage” you can define how this works here by selecting dice types for when the buttons should show up

• Advantage Name

  • If your ruleset calls it something like “Boon” you can change the name here

• Advantage Short Name

  • The short name rendered in the Dice Tray, example “ADV”

• Disadvantage Name

  • If your ruleset calls it something like “Bane” you can change the name here

• Disadvantage Short Name

  • The short name rendered in the Dice Tray, example “DIS”

Common Script

Here you can define all the functions you want available throughout your ruleset. You should place all common code here so that you are not re-defining it in all your scripts and records. Examples of what you might want to place in the Common Script would be functions to double dice damage, parse damage types from roll strings, collect effects and modifiers on a record or token, alter a record or token’s data when an attribute is changed, and so on.

Effects System

The Effects system allows you to create dynamic character modifications through rules that modify token data when applied. Effects can stack, have durations, present user choices, and are fully reversible when removed.

Keep in mind, that if you are leveraging ruleset defined effects (such as "saveBonus" or "savePenalty" in 5e) your Ruleset code needs to account for this. You can take a look at the code in the Common Script of the 5e system to see how Modifiers are collected for Effects (and built-in ruleset modifiers, via the Modifier List, but that is separate from the Effects System.)

Effect Management API

addEffect(effectName, actorToken, effectDuration?, effectValue?, callback?)

Adds an effect to a token by Effect Name. The effect must exist in the campaign.

• effectName (string) — Name of the effect

• actorToken (object) — The target token to apply the effect to

• effectDuration (number, optional) — Duration in seconds. Overrides the effect's default duration

• effectValue (string | token, optional) — A custom value to store with the effect. If a token object is passed, it becomes the caster, enabling @caster.data references (see Caster References)

• callback ((record) => void, optional) — Called after the effect is applied, with the updated record

addEffects(effectNames, actorToken, effectDuration?, effectValue?, callback?)

Adds an array of effects to a token by Effect Names. All effects must exist in the campaign. Duplicate effects are only applied if they are stackable or allowsMultiple (e.g., ['Stunned', 'Stunned'] applies Stunned x2 if the Stunned effect is stackable or allowsMultiple).

addEffectById(effectId, actorToken, effectDuration?, effectValue?, callback?)

Adds an effect to a token by Effect ID. The effect must exist in the campaign.

addEffectsByIds(effectIds, actorToken, effectDuration?, effectValue?, callback?)

Adds an array of effects to a token by Effect IDs. The effects must exist in the campaign. Duplicate effects are only applied if they are stackable or allowsMultiple (e.g., ['Stunned', 'Stunned'] applies Stunned x2 if the Stunned effect is stackable or allowsMultiple).

addTokenChangeEffect(npcId, actorToken, callback?)

Adds an effect to the actor token that changes their token image and size to match the given NPC. That NPC must exist in the campaign.

removeEffectById(effectId, actorToken, callback?)

Removes the effect with the given Effect ID from the token. All data modifications made by the effect are reversed.

deductEffectById(effectId, actorToken, callback?)

Deducts 1 stack of a stacked effect. If it was the last instance or was not a stacked effect, removes it entirely.

// Add a "Poisoned" effect for 60 seconds
api.addEffect("Poisoned", targetToken, 60);

// Add effect by ID with a custom string value
api.addEffectById("effect-id-1", targetToken, undefined, "Concentration on Bless");

// Add effect with the caster token (enables @caster.data references)
api.addEffect("Hex", targetToken, 60, casterToken);

// Add multiple effects by ID with caster
api.addEffectsByIds(["effect-1", "effect-2"], targetToken, undefined, casterToken);

// Change token appearance to an NPC
api.addTokenChangeEffect("npc-wolf-id", characterToken);

// Remove an effect
api.removeEffectById("effect-id-1", targetToken);

// Deduct one stack of a stacked effect
api.deductEffectById("effect-id-1", targetToken);

Rule Types

Each effect contains an array of rules that define what happens when the effect is applied. Rules are processed in order.

Data Rules

Modify individual character fields using mathematical operations. Maintains a history stack so changes are properly reversed when the effect is removed.

{
  "type": "data",
  "value": {
    "field": "ac",
    "operation": "add",
    "value": 2,
    "min": 0,
    "max": 30
  }
}

Operations:

• add — Adds value to current field (works for both numbers and strings)

• subtract — Subtracts value from current field (numbers only)

• multiply — Multiplies current field by value (numbers only)

• divideRoundDown — Divides and rounds down (numbers only)

• divideRoundUp — Divides and rounds up (numbers only)

Override Rules

Replace or merge complex nested data structures. Supports deep merging, expression evaluation, @record.data and @caster.data references, and can reference choice values. Original values are stored in a snapshot for restoration when the effect is removed.

// Simple override
{
  "type": "override",
  "value": {
    "ac": 18,
    "speed": 30,
    "senses": "Darkvision"
  }
}

// Override with expressions
{
  "type": "override",
  "value": {
    "ac": "15 + @record.data.dexMod",
    "hitPoints": "@record.data.level * 10",
    "spellDC": "8 + @caster.data.proficiencyBonus + @caster.data.spellcastingMod"
  }
}

Features:

• Deep Merging — When the current value is an object, nested properties are merged rather than replaced

• Expression Evaluation — Values can contain @record.data, @caster.data, @effect.count, @roll(), inline math, and logical functions

• Array Handling — Arrays from the override are appended to existing arrays

• Snapshot Storage — Original values are saved automatically for restoration on removal

• Expression Evaluation — Values can contain @record.data, @caster.data, @effect.count, @effect.sourceCount, @roll(), inline math, and logical functions

ChoiceSet Rules

Present a modal to the user, allowing them to choose from predefined options. The chosen value is stored and can be referenced by other rules in the same effect via @record.data.

{
  "type": "choiceSet",
  "field": "data.effects.rage.damageType",
  "valueType": "string",
  "value": {
    "prompt": "Select Damage Type",
    "choices": [
      { "label": "Fire", "value": "fire" },
      { "label": "Cold", "value": "cold" },
      { "label": "Lightning", "value": "lightning" }
    ]
  }
}

Notes:

• Choice values can contain @record.data and @caster.data expressions — they are automatically resolved

• Multiple choiceSet rules in one effect prompt sequentially

• If the user cancels any choice, the entire effect is not applied

• Other rules can reference the chosen value via @record.data.effects.{effectName}.{property}

ChoiceSet with fromData

Dynamically generate choices from the token's own data:

{
  "type": "choiceSet",
  "field": "data.selectedWeaponId",
  "value": {
    "valueType": "fromData",
    "dataPath": "inventory",
    "labelPath": "name",
    "valuePath": "_id"
  }
}

Aura Rules

Create an area of effect around a token that automatically applies another effect to tokens within range.

{
  "type": "aura",
  "value": {
    "range": "10",
    "color": "#03c3e8",
    "faction": "enemy",
    "effectId": "effect_id_to_apply"
  }
}

Notes:

• Auras are only processed by the GM

• Affected tokens receive the effect with an effectValue object of shape { _id, name, isAura: true, sourceCount }, where sourceCount is the source's current stack count of the parent aura effect

• When tokens move out of range, the aura effect is automatically removed

• Aura updates are throttled (1 second max) for performance

Referencing the aura source's stack count from the applied effect

The effect applied by an aura (the effectId in the aura rule) can reference the source's stack count of the parent aura effect via @effect.sourceCount. Useful when the aura's behavior should scale with the source's stacks without the source having to write that count to its own data.

The aura layer automatically re-applies the linked effect on affected recipients whenever the source's stack count changes, and rapid changes are debounced so only one reapply fires after the source settles.

{
  "tacticsDie": "ternary(eq(@effect.sourceCount,1),'d4',ternary(eq(@effect.sourceCount,2),'d6',ternary(eq(@effect.sourceCount,3),'d8','d12')))"
}

Light Rules

Add a dynamic light source to a token that casts light in the VTT environment.

{
  "type": "light",
  "value": {
    "range": "20",
    "color": "#ffaa00",
    "intensity": 2.5,
    "angle": 0,
    "flicker": 0.3,
    "falloff": 0.5
  }
}

Expression Syntax

Override rules, aura/light ranges, duration rolls, and choice values all support a rich expression language.

References

Math Expressions

When an entire value is a math expression, it is automatically evaluated:

"ac": "10 + @record.data.dexMod + @record.data.level"
"hp": "@record.data.level * 8 + @record.data.conMod"
"bonus": "(@record.data.strength - 10) / 2"

Supported operators: +, -, *, /, ()

Supported functions: floor(), ceil(), min(), max(), abs()

Inline Math with Curly Braces

Use {expression} for math expressions embedded within strings:

"description": "Attack bonus: {5 + @record.data.level}"
"damage": "{4 + @record.data.level}d6"
"text": "Deal {@record.data.level * 2} damage"

Everything inside {...} is evaluated as a math expression and the result replaces the entire block. Multiple {...} blocks in one string are all evaluated independently.

Instant Dice Rolls

Use @roll(XdY) to roll dice at effect application time. The result is rolled once and cached — the same @roll() expression used in multiple rule values within the same effect produces the same number.

"curhp": "@record.data.curhp + @roll(2d6)"
"tempHp": "@roll(2d10) + @record.data.level"

Logical Functions

Merge Expressions

Use @merge(@record.data.path) to merge an entire object from another source into the target field. When the target already exists as an object, properties are deep-merged recursively.

// Replace or merge an entire object
"strikes": "@merge(@record.data.effects.dragonForm.strikes)"

// Define base values and merge in additional values with __merge
"strikes": {
  "claw": { "damage": "1d6", "traits": ["agile"] },
  "tail": { "damage": "2d6" },
  "__merge": "@merge(@record.data.effects.dragonForm.strikes)"
}

Caster References

When adding an effect, you can pass a token as the effectValue parameter to set it as the caster. The system automatically detects that it's a token (by checking for an _id property) and makes its data available through @caster.data references. This allows the effect to scale based on the caster's stats rather than the target's.

// Pass the caster token so the effect can reference their stats
api.addEffect("Hex", targetToken, 60, casterToken);
api.addEffectById("spell-effect-id", targetToken, undefined, casterToken);
api.addEffectsByIds(["effect-1", "effect-2"], targetToken, undefined, casterToken);

Where @caster.data works

If no caster token is provided (or effectValue is a string), @caster.data references resolve to 0. For duration rolls specifically, they fall back to 1 (or a custom fallback with the pipe syntax: @caster.data.field|2).

Caster Resolution

When a token is passed as effectValue, the system automatically fetches the full caster record if needed (e.g., if only a token stub with _id was provided). This lookup is performed only once per effect application, only when at least one rule references @caster.data.

Example: Spell Effect with Caster Scaling

// Effect JSON
{
  "name": "Inspire Courage",
  "durationRoll": "[email protected]",
  "durationUnit": "rounds",
  "rules": [
    {
      "type": "data",
      "value": {
        "field": "attackBonus",
        "operation": "add",
        "value": 1
      }
    },
    {
      "type": "override",
      "value": {
        "inspiredBy": "@caster.data.name",
        "inspireDC": "8 + @caster.data.proficiencyBonus + @caster.data.charismaMod"
      }
    }
  ]
}

// API call
api.addEffect("Inspire Courage", targetToken, undefined, bardToken);

Dynamic Duration Rolls

Effects can use a durationRoll field to roll their duration dynamically when applied. The roll string supports @record.data, @caster.data, pipe fallbacks, and inline math.

{
  "name": "Bless",
  "durationRoll": "[email protected]|2",
  "durationUnit": "rounds",
  "rules": [...]
}

Fallback behavior for duration rolls:

• @record.data.field falls back to 1 if the field is missing

• @caster.data.field falls back to 1 if no caster or field is missing

• Use the pipe syntax (@caster.data.field|N) to specify a custom fallback value

Note: The durationRoll field takes precedence over the static duration field, but a duration explicitly passed at application time (e.g., the effectDuration parameter in the API) takes precedence over both.

Effect Properties

Common Patterns

Choice + Override

{
  "rules": [
    {
      "type": "choiceSet",
      "field": "data.effects.dragonForm.type",
      "valueType": "object",
      "value": {
        "prompt": "Select Dragon Type",
        "choices": [
          {
            "label": "Fire Dragon",
            "value": "{ \"ac\": \"18 + @record.data.level\", \"damageType\": \"fire\" }"
          },
          {
            "label": "Ice Dragon",
            "value": "{ \"ac\": \"20 + @record.data.level\", \"damageType\": \"cold\" }"
          }
        ]
      }
    },
    {
      "type": "override",
      "value": {
        "ac": "@record.data.effects.dragonForm.type.ac",
        "breathDamageType": "@record.data.effects.dragonForm.type.damageType"
      }
    }
  ]
}

Caster-Scaled Spell

{
  "name": "Bestow Curse",
  "durationRoll": "@caster.data.level",
  "durationUnit": "rounds",
  "rules": [
    {
      "type": "override",
      "value": {
        "curseDC": "8 + @caster.data.proficiencyBonus + @caster.data.spellcastingMod",
        "curseSource": "@caster.data.name"
      }
    },
    {
      "type": "data",
      "value": {
        "field": "savingThrowPenalty",
        "operation": "subtract",
        "value": 2
      }
    }
  ]
}

// Applied via:
api.addEffect("Bestow Curse", targetToken, undefined, casterToken);

Level-Based Scaling with Ternary

{
  "type": "override",
  "value": {
    "proficiencyBonus": "ternary(lt(@record.data.level, 5), 2, ternary(lt(@record.data.level, 9), 3, ternary(lt(@record.data.level, 13), 4, ternary(lt(@record.data.level, 17), 5, 6))))"
  }
}

Dynamic Aura with Choice

{
  "rules": [
    {
      "type": "choiceSet",
      "field": "data.effects.aura.range",
      "valueType": "number",
      "value": {
        "prompt": "Select Aura Range",
        "choices": [
          { "label": "5 feet", "value": "1" },
          { "label": "10 feet", "value": "2" }
        ]
      }
    },
    {
      "type": "aura",
      "value": {
        "range": "{5 * @record.data.effects.aura.range}",
        "color": "#03c3e8",
        "faction": "enemy",
        "effectId": "debuff_effect_id"
      }
    }
  ]
}

Base + Merge

{
  "type": "override",
  "value": {
    "strikes": {
      "claw": { "damage": "1d6", "traits": ["agile"] },
      "tail": { "damage": "2d6" },
      "__merge": "@merge(@record.data.effects.form.strikes)"
    }
  }
}

Effect Application Order

1. ChoiceSet rules prompt the user and store values

2. Choice values with @record.data or @caster.data expressions are resolved

3. If any rule references @caster.data and only a token stub was provided, the full caster record is fetched (once)

4. Data rules are processed and applied

5. Override rules are processed with access to choice values and caster data

6. Duration is calculated (static, rolled, or passed via API)

7. All changes are committed atomically

Effect Removal

• Data rules: Restore values from the operation history stack

• Override rules: Restore values from the stored snapshot. For partial removal of a stackable override effect with stacks remaining, the snapshot is preserved and the override is re-evaluated at the decremented count so @effect.count-dependent fields stay correct across repeated removals. On full removal (or when partial removal brings stacks to 0), the snapshot is wiped.

• ChoiceSet rules: Clear the stored choice value

Best Practices

• Use namespaced field paths for choices: data.effects.{effectName}.{property} (e.g., data.effects.dragonForm.type)

• Use curly braces for inline math: "{4 + @record.data.level}d6" not "4 + @record.data.level d6"

• Always use full prefixes: @record.data.field and @caster.data.field

• Initialize target fields as empty objects {}, not null, when they will receive override merges (MongoDB cannot create fields inside null)

• Test with missing data: Missing @record.data resolves to 0; missing @caster.data resolves to 0 in overrides

• Put expressions in choice values, not in the override — they are evaluated once when the choice is made