Flame

Part of a turn in fire (eg. Running through flames) you take 1d-3 burning damage.
If you spend all of your turn in fire (or are on fire) you take 1d-1 damage per second.

Very intense fires, molten metal, or a furnace would cause 3d per second!

Catching Fire
A single hit that causes at least 3 points of burning damage ignites part of the target's clothing.
This does 1d-4 damage per second and is distracting (-2 to DEX, unless the damage simply cannot harm the target)
Putting it out requires a DEX roll as part of a Ready Maneuver.

A single hit that causes 10 or more burning damage ignites all of the victim's clothes
This does 1d-1 burning damage per second and is very distracting (-3 to DEX, except when putting out the fire)
Putting it out requires rolling on the ground. This requires a DEX roll and each attempt requires 3 Ready Maneuvers.
Jumping into water takes only one second and puts out the fire.
If a wooden shield takes 10 or more burning damage in 1 second the bearer is at -2 to DEX and takes 1d-5 burning damage per second until he gets rid of it.

If using Shock penalties due to damage, be sure to apply them to DEX checks.

Armor does not burn, and protects clothing underneath.

See Heat