What follows is an attempt to systematize the various 'catching on fire' rules found in the DMG, PHB, and MM. I found them to be inconsistent, and rewrote them in an attempt to provide consitency. Please feel free to comment on them.
-- tmaas
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A creature/object is at risk of catching on fire whenever it is exposed to a non-instantaneous fire source and it is flammable.
While still exposed to the fire source and also “on fire”, a creature/object takes damage from both independently.
When a creature is at risk of catching fire:
Make a Reflex save (DC 15).
Failure: clothes or hair have caught on fire. Take 1d6 points of fire damage immediately (this damage is in addition to any caused by the fire source itself). The fire will burn for 1d4 rounds (including the current round) if not extinguished sooner. If the object/creature was already on fire before failing this save, the fire burns for 1d4 rounds or the remainder of the previous duration, whichever is longer.
Success: clothes or hair have not caught on fire; unless otherwise specified, the original fire source is unaffected.
Note: the Reflex save DC may change depending on the intensity/contact level of the fire source. Also, apply appropriate modifiers if the target is more/less “flammable” than usual.
Each round when a creature is on fire:
Creature may attempt to extinguish the fire (see below). If it fails/does not try to extinguish the flames, it takes another 1d6 points of fire damage (again, this is in addition to any damage caused by the fire source, if still exposed to it).
Attempting to extinguish the flames:
Jumping into water: automatic success.
Extinguish Flames (full-round action): make a Reflex save (DC 15). If successful, the fire has gone out and the creature takes no damage from “catching on fire” for the round. (They may take damage from the fire source, if still exposed.)
Modifier: roll on the ground (go prone) or smother with a cloak, blanket, etc. for a +4 bonus to the Extinguish Flames save attempt.
Note: These rules assume the creature is no longer exposed to the fire source. If still exposed, increase the Reflex save DC or decrease the “roll on ground” modifier as appropriate.
Effect on clothes or equipment:
Make a Reflex save (DC 15) for each flammable item (e.g., clothing). Items that fail sustain the same amount of damage as the creature.
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Comments on the “Catch on Fire” rules:
Unfortunately, the “catch on fire” rules in the core D&D rulebooks are inconsistent. The above is a synthesis of various rules found in the PHB, DMG, and MM and a little logic. The key concept is that exposure to a fire source puts a creature at risk of catching on fire, but damage from the fire source and damage from catching on fire (if the creature fails its save) is considered separately. By logical extension, while still exposed to the fire source an “on fire” creature takes damage from both the fire source and being “on fire”, and it is also harder to extinguish the fire itself (how much harder depends on the nature of the fire source). After exposure to the fire source ends, the fire will burn itself out naturally in a few rounds.
Most natural fires/heat sources and magical flames which last for more than one round are considered non-instantaneous. Most magical fires attacks (e.g., fireball) are considered instantaneous. A creature is flammable if it has hair, a flammable body (e.g., made of wood), or is wearing flammable objects (e.g., clothing).
The above rules and DCs all assume a typical humanoid character who is dry and is wearing regular clothing. Apply modifiers as needed if the situation deviates from this norm (e.g., give a +2 bonus to the reflex save if a character is exposed to fire after just being doused in water).
Source material:
PHB 113 (Alchemist’s Fire)
DMG 86 (Catching on Fire)
MM 83 (Fire Elemental)
MM 175 (Thoqqua)
-- tmaas
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A creature/object is at risk of catching on fire whenever it is exposed to a non-instantaneous fire source and it is flammable.
While still exposed to the fire source and also “on fire”, a creature/object takes damage from both independently.
When a creature is at risk of catching fire:
Make a Reflex save (DC 15).
Failure: clothes or hair have caught on fire. Take 1d6 points of fire damage immediately (this damage is in addition to any caused by the fire source itself). The fire will burn for 1d4 rounds (including the current round) if not extinguished sooner. If the object/creature was already on fire before failing this save, the fire burns for 1d4 rounds or the remainder of the previous duration, whichever is longer.
Success: clothes or hair have not caught on fire; unless otherwise specified, the original fire source is unaffected.
Note: the Reflex save DC may change depending on the intensity/contact level of the fire source. Also, apply appropriate modifiers if the target is more/less “flammable” than usual.
Each round when a creature is on fire:
Creature may attempt to extinguish the fire (see below). If it fails/does not try to extinguish the flames, it takes another 1d6 points of fire damage (again, this is in addition to any damage caused by the fire source, if still exposed to it).
Attempting to extinguish the flames:
Jumping into water: automatic success.
Extinguish Flames (full-round action): make a Reflex save (DC 15). If successful, the fire has gone out and the creature takes no damage from “catching on fire” for the round. (They may take damage from the fire source, if still exposed.)
Modifier: roll on the ground (go prone) or smother with a cloak, blanket, etc. for a +4 bonus to the Extinguish Flames save attempt.
Note: These rules assume the creature is no longer exposed to the fire source. If still exposed, increase the Reflex save DC or decrease the “roll on ground” modifier as appropriate.
Effect on clothes or equipment:
Make a Reflex save (DC 15) for each flammable item (e.g., clothing). Items that fail sustain the same amount of damage as the creature.
-----
Comments on the “Catch on Fire” rules:
Unfortunately, the “catch on fire” rules in the core D&D rulebooks are inconsistent. The above is a synthesis of various rules found in the PHB, DMG, and MM and a little logic. The key concept is that exposure to a fire source puts a creature at risk of catching on fire, but damage from the fire source and damage from catching on fire (if the creature fails its save) is considered separately. By logical extension, while still exposed to the fire source an “on fire” creature takes damage from both the fire source and being “on fire”, and it is also harder to extinguish the fire itself (how much harder depends on the nature of the fire source). After exposure to the fire source ends, the fire will burn itself out naturally in a few rounds.
Most natural fires/heat sources and magical flames which last for more than one round are considered non-instantaneous. Most magical fires attacks (e.g., fireball) are considered instantaneous. A creature is flammable if it has hair, a flammable body (e.g., made of wood), or is wearing flammable objects (e.g., clothing).
The above rules and DCs all assume a typical humanoid character who is dry and is wearing regular clothing. Apply modifiers as needed if the situation deviates from this norm (e.g., give a +2 bonus to the reflex save if a character is exposed to fire after just being doused in water).
Source material:
PHB 113 (Alchemist’s Fire)
DMG 86 (Catching on Fire)
MM 83 (Fire Elemental)
MM 175 (Thoqqua)
