Since there's been some hubbub lately about this Mortal Kombat movie-pitch thingy, I figured it would be appropriate for a Mortal Kombat themed tip.

So, in Ultimate Mortal Kombat 3, after choosing your characters, you come up to the Vs. Screen, which has this row of symbols across the bottom.

Which you and your opponent can manipulate by pressing the buttons on your respective side of the cabinet. So, say you both press Low Punch exactly one time so that the display looks like this

Then when the match starts, you'll get confirmation at the bottom of the screen that the code worked

This one, for instance, disables throwing, so you have to beat up your opponent the old fashioned way... with punches, kicks, and special moves.