I couldn't let a new fall semester roll around without loudly proclaiming the greatest thing to come out of my second year of grad school: hall pong. Born out of a combination of ping-pong, racquetball, hockey, and sheer boredom, hall pong is a perfect way to procrastinate (and pretend to get some exercise) when you're stuck in a basement office.

Classic hall pong is a two-player sport. It's played in a hallway, with a goal line of some sort on the floor at each end (it could be a change in the floor tile pattern, or the base of a doorway, or you could just mark it with tape), using a ping-pong ball and two paddles (one per player). The Official Rules are simple:

1. You score a point when the ball hits the floor behind your opponent's line.
2. Whenever anyone other than the players enters the hallway, play stops until they have passed through. (This is a safety issue)
3. Don't be a dick.

That's it. Well, actually rule #3 is more of a guideline. But if you routinely do things like carrying the ball up to your opponent's end of the hallway and spiking it behind their goal line (which is technically legal), the sport loses its appeal pretty fast. Hall pong is supposed to be fun.

If that's not enough for you, here are some conventions and clarifications that have developed to supplement the Official Rules.

• The ideal playing court is a hallway about 15 meters long, or about as far as you can hit a ping-pong ball before it bounces.
• At the beginning of the game, both players retreat to a starting position just in front of their goal lines. The player with the ball starts the game with a serve. That generally entails either throwing the ball up or bouncing it on the floor, and then hitting it as hard as you can, but anything goes.
• The ball has to travel past the middle of the court for a serve to count.
• There's no penalty for missing a serve; you get to try as many times as you want.
• You can use your paddle or any part of your body to keep the ball from going behind your goal line.
• Try to avoid actively hitting the ball with a part of your body. The paddle is for offense; body parts are for defense.
• Catching the ball is acceptable but generally discouraged, except when necessary for defense. After you catch it, both players return to their starting positions, as at the beginning of the game. Then you restart play by serving the ball.
• If the ball is rolling on the floor, you can just pick it up and proceed as with a catch.
• Whenever a point is scored, play immediately stops until the ball is served by the player who was scored on.
• The offsides guideline: stay at least a quarter of the hall length away from your opponent's goal line, unless your opponent is further away from the line than you are. This definitely falls under Official Guideline #3, so it's subject to being broken whenever necessary to make a really cool play.
• Games are played to 5 points, or until the ball breaks.

That last point bears mentioning again: the ball will break. As in, literally crack in half (or smaller pieces, if you're good). Evidently ping-pong balls don't stand up to a lot of high-velocity impacts, so you'll want to have plenty of extras on hand.

Of course, hall pong is subject to many possible variations. You can play in a hallway with closed ends, in which case rule #1 is modified to say that you score a point when the ball hits the door or wall behind your opponent. Using a shorter hallway gives you a faster paced game (and better reflex training); alternatively, this may be good for players who have weaker swings. There are endless ways to formulate the offsides rule — I mean guideline — you may want to make it more or less restrictive depending on who's playing, and you can even make it asymmetric to handicap one player. Or dispense with it entirely.

What I'd really like to do is play in a hallway with air vents in the floor, like a high-powered air hockey table, so the ping-pong ball effectively floats. Or even better, play in a zero-gravity environment. I bet this game could fit perfectly in some of the cramped spaces on the space shuttle or ISS ;-) Wishful thinking, sure, but it sounds more fun than getting a Ph.D. Anyway, until then, happy playing!