D&D’s Fundamental Rules

Combat Rules: Armour Class

Armour class is something that comes up in every single combat encounter, no matter what. Armour class is fundamental to D&D combat, as it determines whether or not a player gets to role damage for an attack.

Armour Class should not be thought of as whether or not you hit an enemy, but whether or not any damage was inflicted on the enemy e.g. even though the arrow hit the dragon the dragons scales were to hard for the arrow to pierce, therefore no damage was inflicted on the dragon, this hypothetical dragon would therefore have a high Armour Class .

The Mechanics of Armour Class

Armour class is displayed as a number usually between 1 and 20, although some very high level monsters and players may surpass this range.

When a player or a monster rolls a dice to make an attack if the number they rolled (after adding any relevant modifiers) is equal or more than the Armour class of their target then the attack is a success and they would roll another dice to determine how much damage they did to the target.

However if the player/monster makes an attack role and the number role is less than the target Armour class then the attack fails and they do no damage.