Saeviomagy
Adventurer
They have an idea, but adventurers "have an idea" that monsters are in a dungeon. That doesn't mean they never get ambushed.A battle breaks out (initiative was just rolled). Rogue, who starts out visible to all, moves behind cover (gaining Total Cover, or Superior Cover, whatever it is called). He then makes a very high Stealth check (beating everyone's Perception checks). Next round, he wants to make a Ranged Sneak Attack. Let's say he does this, and he hits. Would it be Sneak Attack damage?
The NPCs saw where he ran off to, so it's not like they don't have an idea of where he is.
SITUATION 2
(This is probably covered right in the rules)
A battle breaks out (initiative was just rolled). Rogue, who starts out visible to all, moves behind cover (gaining Total Cover, or Superior Cover, whatever it is called). He then makes a very high Stealth check (beating everyone's Perception checks). Next round, he wants to move from his cover to another area of cover 5 squares away. Does the Stealth check allow him to do this w/o being seen during his movement? Even if he is out in the open for a few squares until he gets to the next area of cover?
Nope, he's spotted. UNLESS he has that rogue utility power which specifically allows him to do this (as long as he ends his turn in cover... UNLESS he has the utility power which lets him hide totally out in the open).
Oh, incidentally if there are any monsters who's line of sight to him is still obscured, he's still hidden to those monsters.