It doesn't really happen too much any more, but you might run into this scenario some time.

Make your way to an arcade and notice that there are lots of people standing around some machine. On the glass, you might notice that there is a line of quarters or tokens lining the bottom of the glass.

These have been put there by the folks gathered around to watch the game. Each one is someone's place in line to be next at the game. Once the game's over, the loser walks away and the person who's quarter is next in line gets to play.

You do have to do a little work to remember which coin is yours if there's more than about 4 up there. But it's worth it to make sure everyone gets their fair shake at whatever the new game happens to be.

Just make sure you don't immediately put in another of your quarters if you should lose and there are coins waiting on the bezel. That's just rude.