Armour and Dexterity Modifiers
Each class of armour has a maximum AC bonus you can gain from Dexterity. No Armour: +3, Leather: +2, Chain: +1, Plate: 0. Magical armour counts as one class "lighter", so Magical Chain would allow a character to use up to +2 for Dexterity.
Light Weapons and Skillful Warriors
A character can use their Dexterity Modifier instead of Strength Modifier for to-hit rolls with the following weapons: Dagger, Short Sword, Staff. Small races (Hobbits etc) can only use their Dexterity Modifier with a Dagger.
Two-Handed Weapons and Strong Warriors
A character can only gain up to a +1 modifier to hit / damage unless they are wielding one of the following weapon in two hands: Club, Hand-Axe, Mace, Spear, War Hammer, Battle Axe, Sword, Pole Arm, Two-Handed Sword.
Beasts and Fire
Beast-like monsters which fear fire (most animals do) must make a Morale check each round before they are able to attack a character holding a lit torch, or attempt to cross a pool of burning oil. They must also make an extra Morale check any time they are attacked with fire (Torch, Flaming Oil, Magic)
Characters at 0 Hit Points
As per Weird West:
Characters reduced to 0 Stamina Points by a non-lethal attack are knocked unconscious for the remainder of the fight. If a character is at 0 Stamina Points after being hit by a lethal attack roll d6 (table on page 5).
Non-lethal Combat
As per Weird West:
Half Stamina Point loss is temporary and regained after the fight.
If weapon roll is more than half of remaining Stamina Points, the defender is stunned and loses their next action. A stunned target hit by another attack is knocked unconscious for 1d4 rounds.
If weapon roll is more than half of remaining Stamina Points, the defender is stunned and loses their next action. A stunned target hit by another attack is knocked unconscious for 1d4 rounds.