On Fire
You are on fire. At the start of your turn you suffer the On Fire damage dice, then attempt a Dodge Check with DC 12 + number of On Fire damage dice to try to put it out.
If you succeed, you reduce the number of On Fire damage dice by 1, +1 for every 5 by which you succeed. The fire is put out when the damage is reduced to 0 dice.
If you fail, the fire grows, increasing the On Fire damage dice by 1 (or 2 on a crit fail).
Naturally, submerging yourself in water puts out the fire. Dousing yourself in water automatically removes one On Fire damage die per liter of water used.