I have a rogue character that has been specializing in stealth. I started to notice it had some interesting results and wished to report them back here. Naturally I think it has to do with your skill versus the level of the monster so your results may vary. 40ish: You can pull small groups from the monster zoo and not aggro everyone at once. You can easily escape from anyone more than 2 squares away and they forget about you. 50ish: Monsters will not notice you unless you are very close to them, and you don't wake up sleeping enemies by attacking adjacent allies anymore. 60ish: About half of the time, you can fight monsters next to each other and they still won't notice you for a round or two. 70ish: You can walk into a zoo and kill them one by one and nobody but the person you are attacking will notice you.
I have around 40ish and monsters still notice me from miles away,wake up once i hit someone 3-4squares away and zoos are alarmed the moment I make one step. Even monsters that say "The monster hasn't noticed you",always move towards me. Does the way a monster is facing, has any effect if they notice you or not? I noticed that most of the time if they are turned away from me, they won't notice me,but they still move towards me facing the other way.
I think facing may have something to do with it. For instance, when a monster faces me he may still generally move towards me. However when he gets to me he doesn't attack and just wanders around me. Of course the chance of being detected is way higher if he is adjacent and looking at you, but I still don't get attacked by most monsters even adjacent to me unless I start beating on them.
I'm building a more-or-less pure rogue character, I've reached 70 or so stealth around dungeon level 8 without even trying (mostly coming from high primary stats). It is indeed excellent for dealing with a zoo; you will get spotted (too many monsters so it becomes a statistical certainty) but a monster is as likely to walk straight past you as to spot you, so it's easy to manage.
Animation: You should be looking for the sneakiness secondary stat. It falls under nimbleness. So every skill which increases nimbleness should also influence your sneakiness. The burglary, archaeology and artful dodger skills increase your nimbleness.
Even my wizard, from burglary and archaeology alone, has like ~60 sneakiness. Other than a few special enemies, most things just seem to ignore me.
Just FYI, from watching enemies move about it seems like they don't move around purely at random; they seem to pick a direction, walk that way for a little bit, and then turn in a different direction. Thus, if you are standing somewhere and a monster doesn't notice you, there's a 1 in 4 (maybe 1 in 3, I don't know if they'll turn around and go backwards) chance that it will walk towards you anyway. Just wait a little bit and it should change direction.
