Strength affects both the amount of damage you do as well as your chance of hitting an opponent.
Dexterity adds to your AC, which increases your chance of blocking an attack.
Wisdom is used to calculate how much experience you'll gain from a fight.
Constitution is related to the number of hit points you have.
Increases chances in a fight while using a weapon. Also used to determine what weapons your character can equip.
Defense: Increases chances of defending yourself in a fight. Also used to determine what armor your character can equip.
Increases chances in a fight while not using a weapon.
Increases chances of unlocking a door.
Increases chances of disarming a trap.