IGNITE FIRE AND CREATE FIRE SPELLS: Fireballs deal their listed damage. Walking in burning hexes are listed below....
NORMAL BURNING DAMAGE: If you spend a part of your turn in a burning hex, you take 1d-3 damage. If you spend your whole turn in the fire, you take 1d-1 damage. Unless you are an armored target - see below to "Burning an Armored Foe."
BURNING CLOTHES:
4 points of fire damage at once or Ignite Fire at its third level will set someone's clothing on fire. This is very distracting and causes -2 to DX, and causes 1d-4 damage per turn. It takes 1 turn to beat out the fire with your hands if you succeed a DX roll.
10 full points of flame damage in one turn will ignite all of the victims clothing doing 1d-1 damage per turn. Nothing else can be done until the victim jumps into water or takes three turns of rolling around to dowse the flames.
These rules assume normal clothing. Clothing under Armor is nearly impossible to catch on fire. Normal flame damage is 1d-1. It would almost take an Exploding Fireball at its full strength to catch everyone aflame.
BURNING AN ARMORED FOE: Low tech armor protects completely from flame for a number of turns equal to the armors DR x 3. After that, the victim rolls vs HT to resist the fire. A failed roll causes 1 fatigue in damage, plus burning damage according to the lowest level of armor DR you are wearing.
EG, Leather Armor has DR3. A foe wearing leather armor is completely immune to fire of normal heat for six seconds. After that, the victim rolls HT to resist the flame. S/He starts taking fire damage now, with armor protecting.