Question that's bugging me, why did CoX have 2 Aiming statistics? ToHit and Accuracy (one being an additive percent and one being a multiplier) I mean I get the whole "you have to have something higher than 1 to multiply by" factor but why not just leave it at the additive percent? are there any fans of 2 aiming statistics? how adamant are you about them and why?
Amplifying Super Firebug's post:
Everything in CoH had a base chance to hit value, which was that entity's base chance to hit a target by default (for players, this was 75%). The target's Defense subtracted from that, so it was logical that attackers be given a way to increase that; thus, tohit buffs.
These apply to all attacks. But what if you want to make an individual attack more accurate (likely to hit) than the average attack for a given attacker? Hypothetically speaking, you could have designed City of Heroes with a "tohit bonus" on attacks that would apply only to that attack, but the designers decided instead that they wanted this effect to be proportional: this attack hits twice as often on average, so its overall effect is to be a 2x multiplier. Thus: accuracy buffs.
Its pretty much a straight-forward exercise to realize that there needed to be two kinds of accuracy: one that buffs the entire player, and one that buffs an individual attack, to account for more accurate attackers and more accurate attacks. Why they work differently mathematically is due to what their intent was: player attacker buffs were intended to be the opposite of target defense buffs. Thus, as defense subtracted, tohit buffs added. Attack multiplier buffs were intended to increase the chance to hit by a ratio, thus they are multiplicative. Two different design goals, two different mechanisms and math to achieve them.
Now, if you only want one aiming buff, the question is not "why not both additive" but rather "why not both multiplicative?" See, the original designers did have a moment of clarity when they realized that in different situations they wanted different behavior, but they primarily thought about it in terms of the player being the attacker and the NPCs being the target. If they had thought about it the other way around, they would have realized that additive tohit buffs make it incredibly difficult to balance how player defense powers work. Small magnitude defense powers would be practically worthless when "accuracy" buffs were in play in any amounts, and defense-oriented sets (Ice, SR) would be essentially impossible to make work in reasonable fashion, because of the disproportionate effect of additive tohit buffs (this is what the Issue 7 critter accuracy changes were explicitly designed to address).
The one you *need* is the multiplicative one. Without it, you can't reasonably have defense as a player skill except as a toy feature. The one you don't need, but is logical to have, is the additive one: something that acts as the inverse of defense.
