Game Mechanics: Spell Resist agro?

[Velerin]

As a wizard all through classic, I was always under the impression that agro was always based on potential damage so if you nuke it doesn't matter if it was full, partial or resisted (or crit later on) it had equal amount of hate. A good side benefit of this was that concussion lowered hate whether it resisted or not as well (though not sure if it works that way on p99 since I haven't played a wizzie here).