|4E| Revised Stealth Rules
Some Guy
Right now they are only in the Compendium, but Sage Advice says they
will soon be folded into the official updates. Here's what I copied
from the online page:
Make a Stealth check to conceal yourself from enemies, slink past
guards, slip away without being noticed, and sneak up on people without
being seen or heard.
This skill is used against another creature’s Perception check or
against a DC set by the DM.
STEALTH
Stealth: At the end of a move action.
Opposed Check: Stealth vs. passive Perception. If multiple enemies
are present, your Stealth check is opposed by each enemy’s passive
Perception check. If you move more than 2 squares during the move
action, you take a –5 penalty to the Stealth check. If you run, the
penalty is –10.
Becoming Hidden: You can make a Stealth check against an enemy only
if you have superior cover or total concealment against the enemy or if
you’re outside the enemy’s line of sight. Outside combat, the DM can
allow you to make a Stealth check against a distracted enemy, even if
you don’t have superior cover or total concealment and aren’t outside
the enemy’s line of sight. The distracted enemy might be focused on
something in a different direction, allowing you to sneak up.
Success: You are hidden, which means you are silent and invisible
to the enemy.
Failure: You can try again at the end of another move action.
Remaining Hidden: You remain hidden as long as you meet these
requirements.
Keep Out of Sight: If you no longer have any cover or concealment
against an enemy, you don’t remain hidden from that enemy. You don’t
need superior cover, total concealment, or to stay outside line of
sight, but you do need some degree of cover or concealment to remain
hidden. You can’t use another creature as cover to remain hidden.
Keep Quiet: If you speak louder than a whisper or otherwise draw
attention to yourself, you don’t remain hidden from any enemy that can
hear you.
Keep Still: If you move more than 2 squares during an action, you must
make a new Stealth check with a –5 penalty. If you run, the penalty is
–10. If any enemy’s passive Perception check beats your check result,
you don’t remain hidden from that enemy.
Don’t Attack: If you attack, you don’t remain hidden.
Not Remaining Hidden: If you take an action that causes you not to
remain hidden, you retain the benefits of being hidden until you resolve
the action. You can’t become hidden again as part of that same action.
Enemy Activity: An enemy can try to find you on its turn. If an
enemy makes an active Perception check and beats your Stealth check
result (don’t make a new check), you don’t remain hidden from that
enemy. Also, if an enemy tries to enter your space, you don’t remain
hidden from that enemy.