Active Effect Rules

Rules are a special type of active effect changes provided by the system. Rather than being applied directly to data on an actor or item, these rules are evaluated at roll time and modify only a specific roll.

Categories

Rules are grouped into several categories to control what types of rolls they affect. These categories are entered in the "Attribute Key" field in the change configuration window.

Category	Description	Valid Rule Types
attack	Affects the d20 roll for attacks.	All
check	Affects the d20 roll for ability checks.	All
d20	Affects the d20 roll for any attack, check, or save.	All
damage	Affects the first matching damage part.	Bonus
save	Affects the d20 roll for ability saves, death saves, and concentration saves.	All
healing	Same as with damage, but for healing.	Bonus

Types

There are four different rules that are currently available, bonus, advantage mode, and the range rules (minimum and maximum). All of these rules can be used for d20 rolls, but damage and healing only support bonus rules at this time.

Advantage Mode (d20 rolls only)

This mode can be used to impose advantage or disadvantage on a certain d20 roll. The "Value" field takes a limited number of possible values to indicate how the advantage mode for the roll should be affects:

Value	Description
+1	Add a source of advantage to the roll.
-1	Add a source of disadvantage to the roll.
=+1	Force the roll to have advantage (ignore disadvantages).
=-1	Force the roll to have disadvantage (ignore advantages).
>=0	Ignore any source of disadvantage, but still allow advantage.
<=0	Ignore any source of advantage, but still allow disadvantage.

Bonus

The bonus mode simply adds new parts to a roll. This can be either a static value (e.g. 3 becomes 1d20 + 3), a dice value (e.g. 1d4 becomes 1d20 + 1d4), or a attribute (e.g. @prof becomes 1d10 + @prof which may resolve to 1d20 + 2).

For damage rolls this can also include a damage type annotation. Normally a damage bonus becomes whatever type it was applied to (so adding 1d4 to a rapier's damage means that it is piercing damage), but an annotation can change it to a different damage type (e.g. 1d4[fire] means that extra damage is now fire damage).

Roll Maximum & Roll Minimum (d20 rolls only)

The maximum and minimum rules affect the range of the d20 rolled. This affects strictly the value on the die before any modifiers are applied. Setting a minimum of 10 for example, results in 1d20min10 being rolled and any results on the die below that value become 10.

This also accepts deterministic formulas, so you can enter a minimum of @prof and that will resolve to the proficiency modifier of the person rolling the die.

Conditions

Rules are extremely broad by default. Adding a damage bonus rule means that that bonus is applied to all damage, whether it be from a spell or weapon, melee or ranged, and of any type. To narrow down when a rule is applied, effect & change conditions can be used.

The active effect conditions page goes over the details on how conditions are defined and what data can be generally filtered on. Of special importance to rules is the rolling description fields which provide additional information that can be used to narrow down when a rule should be applied (e.g. using the roll.damage.type to only apply a bonus when the character does fire damage, or roll.attack.mode to apply a bonus only to thrown weapon attacks). Any roll. keys can only be referenced in change conditions, not effect conditions.

Key	Description	Example
roll.ability	Ability associated with a D20 roll.	dex, str, etc.
roll.attack.classification	Source of the attack.	weapon, spell, or unarmed
roll.attack.mode	Selected weapon attack mode.	oneHanded, thrown, offhand, etc.
roll.attack.type	Whether this is a melee or ranged attack.	melee or ranged
roll.damage.type	Type of damage being applied for a single damage part.	cold, fire, etc.
roll.item	Roll data for item performing the attack (while the item) at the top level contains data for the item that provided the rule AE.
roll.proficient	Whether proficiency was added to the roll.	true or false
roll.scaling	Any scaling applied to the item used for the roll.
roll.skill	ID of skill associated with the roll.	acr, ath, etc.
roll.tool	ID of tool associated with the roll.	thief, carpenter, etc.
roll.type	Type of roll being performed.	attack, skill, tool, etc.

Minimum Roll on Ranged Attacks

• Key: attack
• Type: Minimum
• Value: 10
• Condition:

{
  "k": "roll.attack.type",
  "v": "ranged"
}

Damage Bonus on Thrown Weapon Attacks

• Key: damage
• Type: Bonus
• Value: 1d4
• Condition:

{
  "k": "roll.attack.mode",
  "o": "startswith",
  "v": "thrown"
}

Damage Bonus to All Fire Damage

• Key: damage
• Type: Bonus
• Value: @prof
• Condition:

{
  "k": "roll.damage.type",
  "v": "fire"
}

Disadvantage on Strength-Based D20 Tests

• Key: d20
• Type: Advantage Mode
• Value: -1
• Condition:

{
  "k": "roll.ability",
  "v": "str"
}

Bonus on Intelligence (History) & Wisdom (Medicine) Checks

• Key: check
• Type: Bonus
• Value: 1d4
• Condition:

{
  "o": "OR",
  "v": [{
    "o": "AND",
    "v": [{
      "k": "roll.ability",
      "v": "int"
    },{
      "k": "roll.skill",
      "v": "his"
    }]
  },{
    "o": "AND",
    "v": [{
      "k": "roll.ability",
      "v": "wis"
    },{
      "k": "roll.skill",
      "v": "med"
    }]
  }]
}

Bonus on Charisma (Deception, Intimidation, or Persuasion) Checks

• Key: check
• Type: Bonus
• Value: 1d4
• Condition:

[{
  "k": "roll.skill",
  "o": "in",
  "v": ["dec", "itm", "per"]
},{
  "k": "roll.ability",
  "v": "cha"
}]