Quote Originally Posted by WILL View Post
In theory it can be done by recording the player's actions in the game, then as you return (back at the same time) you could litterally end up playing against yourself. Though you wouldn't have that same interaction as if it were really happening. Basically your other version of you would simply ignore you. Unless you code the first REAL game time machine.
Or, you have a really good AI that reconstructs what you should have done if what you do to yourself had happened... and then the rest of the world has to react to push the events to convergence...

I'd better not dig too deep into that.