"Thieves in a MMORPG can sneak up on enemies unseen. This is not very realistic, it disturbs rather less.
In an open field with no bushes, trees or other hiding place sneaks a thief approached a group of enemies that patrol there. He will not be noticed,suddenly he strikes and turns all enemies within seconds.
There's rarely a mmo today without a thief/assassin class . If you take it exactly, then sneaky thieves do not actually on their victims, because they are invisible. Other players and monsters can not see a thief in "stealth mode" , even if this is directly from them. Other players who have nothing whatsoever to do with the situation and the thief would actually see them from their point of view, it does not recognize. This has nothing to do with stealth and could be rather described as magical."