World of Terrabia
The principle mechanics behind Combat are simple.
The attacker rolls 1d20 and adds the appropriate Attribute for Melee Attack, Ranged Attack, or Magic Attack, and the defender rolls 1d20 and adds the appropriate Attribute for Physical Defense or Magic Defense.
If the attack succeeds, then the appropriate damage is rolled, depending on if it is Melee Damage, Ranged Damage, or Magic Damage. Armor and Toughness only mitigates physical damage, and requires magical augmentation to mitigate magical damage.