98% of all RPG mechanics deal with battles. RPG battle mechanics are nothing but pure (and simple and easy) math.
The "hit roll" is used to determine an attacker hits a defender. This pits the attacker's attack stat vs. the defender's defense stat.
- attacker's attack + random roll > defender's defense
Armor and Weapons
Armor and weapons can modify the attack roll on either side in various ways.
This page has been recommended for cleanup, integration, etc.