For top-end IO builds, I like to build for 95% hit chance against +4 enemies. This takes +143% accuracy in powers with normal 75% base ToHit, less if you have Kismet, Tactics or other sources of ToHitBuff.
For SO-only builds, I'm usually content with 2 even-level SOs worth of accuracy, which is the minimum I'd need to feel comfortable.
Two even level SO's worth, approximately 65%, will cap your chance to hit at 95% against +2s, as long as you have no tohit debuffs on you and they have no defense (and you're using a normal base accuracy power). That's my personal aim point, as I don't go for super high-end builds, and I figure if I'm fighting something higher than +2, I'm probably on a team and thus it isn't as critical to cap my CTH out of my own resources. On the other hand, its possible to run into +2s solo even if you're not playing on the highest difficulty, so I want to be able to hit them.
That is, of course, assuming that you don't have any global accuracy/tohit boosts from set bonuses, the kismet unique, or powers like invincibility/tactics. If you do, the math gets a bit more complicated. The base chance to hit a +2 is 56%. If you have any tohit bonuses like the kismet unique, invincibility, or tactics, that simply adds to the 56%. Then, that total is multiplied by your accuracy total. So, for an example, let's say you're using a power with a 0.8 base accuracy (less accurate than usual, most have 1.0), you have 61% accuracy slotted in the power, you have one 7% accuracy bonus from a set, and you have a 6% tohit bonus from invincibility (3 enemies). Your hase tohit against a +2 in that case is 56+6 = 62%, which is then multiplied as 62% * 0.8 * (1.61+0.07) = 83%. You can use the same formula to figure out your chance to hit in a variety of situations.
@MuonNeutrino
Student, Gamer, Altaholic, and future Astronomer.
This is what it means to be a tank!
Still newish to the game and so I don't have a good handle on all the sorts of high-end content and what I should be targeting with a build.
So the question is basically, what are some targets you guys have for accuracy on a build? I.e. what is something that will cap against 90% of the content? Are there other obvious cutoffs I should be looking at? Etc.