Hypothetical - Multiplayer Horror

[Kreekakon]

Thinking of gameplay applications for some of the things said. You could use that "herd behaviour" against players. Example - you have a group of four players. They reach a fork in the road. The players go left. Yet in the game of the one walking most behind, the game mirrors the other player's movement making it look like they're going right instead. For the first three players, his movements are mirrored and it looks like he's going left with them. A minute of corridor or so later, the fake players disappear and the gamers are thoroughly confused. Throw up barriers or whatever to make getting back together more difficult.

A while later the group is back together and for three of them the fourth player's character disappears even though he's still right there.

Okay, so it's not perfect, but it'll likely throw off and confuse players. In a creepy enough atmosphere, it could be really unsettling.

...that's actually a genius move.