According to the RM2k3 help file, this is the damage algorithm of skills:
Damage = Base Damage + (Attack power of A / 20 * Attack influence of skill) + (Defense of B / 40 * Intelligence Influence of skill)
According to this, the attacker's intelligence isn't factored into a skill at all. However, the higher the target's defense, the more damage the target takes if the attack uses intelligence influence. Also, the defender's defense doesn't reduce damage at all, but ends up causing them more damage.
When [Ignore Defense] is checked, the damage algorithm is as below.
(Defense power of B / 40 * Attack influence of skill) + (Intelligence of B / 80 * Intelligence influence of skill)
According to this one, ignoring the opponent's defense actually ignores the attacker's stats altogether and just causes damage based on the defender's Def and Int, both causing more damage as the defender's stats are higher.
I have tested this in test battle using the same enemy and comparing stats I predicted that if these algorithms were correct (at least the first, I haven't tested one that ignores defense) the attack would deal 20 damage. Against the weakest enemy in my game, the hero dealt 20 damage at level 1, and at level 40 dealt about 35 damage.
Does anyone know why the algorithms are set up this way? I want spells that use intelligence offensively so that characters with low attack values can deal more damage with their spells, even though they deal less damage with their normal attacks. How do I go about correcting this problem?