The internal set of morals or the conscience that leads people to make good decisions. Often times this is a person in a group who's friends will turn to for advice for he will never lead them astray.
Example: Guy: what should we do with this extra food?
Guy 2: I don't know, let's ask Landon, he's the moral compass! He'll know exactly what to do.
Example: If her moral compass didn't point to "I win, they lose, I'm awesome!" (something like North), she didn't get the compass, nothing made sense, and somebody had to take control of the compass until it told her "I win, they lose. I'm awesome!" again (at which point everything would make sense again).