This is an idea for a new version of pool ('billiards' to some).
The only physical difference is that the table in this version has extra lines - one down the centre on the long axis, and three crosswise, dividing it into eight zones. (Or perhaps six zones, or simply four quarters; play-testing will
reveal which configuration works best, but eight seems to me to allow for a decent-length game without being overly difficult to keep track of.)
You can indicate these zones with small chalk lines on the side of the table if your pub landlord might frown on you drawing lines on the baize...
Battle pool involves two basic changes to the rules (I'm thinking of UK eight-ball pool rules here, the rules below might need adapting for the US version and especially for nine-ball):
1. Claiming Zones: After a player commits a foul, the opponent has a choice. He/she can either claim the foul as per usual, or take a normal turn but claim an unclaimed zone.
2. Zone Fouls: When an opponent owns a zone or zones, the player commits a foul if he/she leaves the cue ball in one of the opponent's zones.
The winner is determined by normal pool rules, i.e., either potting the black or laughing as your opponent pots the black and goes foolishly in-off or suchlike. You can play your preferred format: single game, best of three, first to ten, or whatever.
Optional additional rules:
A. Safe Zones: When a player owns a zone or zones, he/she is not penalised for a foul shot, *if* the cue ball finishes in one of his/her zones. Exception: potting the black early still loses the game, even if the cue ball finishes in your zone.
B. Capturing: After the opponent fouls, a player may choose to capture one of his opponent's zones instead of claiming a zone or taking the foul. Power zones (described below) cannot be captured.
C. Neutralising: A player cannot directly capture an opponent's zone, but can first neutralise it, and then capture it after another foul.
(Rules B or C may be in force either from the beginning of the game, or only once all zones have been claimed by one player or the other. The latter is definitely better for rule B.)
D. Power Zones: when a player claims a zone for a second time, the opponent is now no longer allowed to pot into that pocket. Balls potted into that pocket are replaced on the table. The side pockets can be claimed by both players, if they each control one of the zones touching the pocket.
E. Super-Power Zones: All zones become power zones immediately after being claimed, without needing to claim them a second time to activate the extra power.
F. War: Rather than all zones being neutralised when the game is finished, the zones carry over into the next game. The winner is the player who gains control of all eight zones - winning individual games counts for nothing.
G. Cold War: As per 'War', but in this version, you can only claim a zone when you win a game. This will probably lead to a long, drawn-out game, with the eventual result becoming clear well before the final victory.
H. Nuclear War: A time limit is agreed. Whoever is in control of more zones 'when the bomb goes off' wins.
(Rules F, G, and H require rules B or C to be in force, and not rule E, or else stalemate is almost certain.)
Differences in gameplay between Battle Pool and Normal Pool:
If you play single games with the basic variation, you might not notice much difference. If both players are half-decent, some games might go by without any fouls by either player.
However, when some of the zones are in play, it does bring extra strategy into the game. Here are some of the questions you might consider depending on the situation:
Do you take the easier shot if it requires more cue-ball control to avoid finishing in your opponent's zone?
Do you claim a zone or take the foul? Which will be more useful to you right now?
Do you choose the zone you claim according to where your opponent's balls are now, or near where the black ball is, as a pre-emptive move if your opponent might get on the black before you?
If you own a zone, and are playing with Safe Zones, do you play one of your opponent's balls to put it in a tricky position, if you can make the cue ball finish in your zone so it's not a foul shot?
If your opponent fouls and you're playing with Neutralising, is it better to neutralise your opponent's zone or claim one of your own?
If you're playing one of the War versions, do you claim a zone in the baulk end which is important for this particular game, or another zone that might be more useful for future games (e.g. one of the corner or middle pocket zones near the pack)?
I'd suggest starting with the basic version while you get used to the rules. After that, adding in Neutralising and Power Zones for a best-of-whatever match would work well if you want an interesting game but still with recognisably pool-like gameplay.
Alternatively, playing either War or Nuclear War, with Safe Zones, Capturing (once all zones claimed) and Power Zones, could see some pretty unusual tactics and gameplay.
I only just thought of this idea. I plan to play-test it soon - assuming that HBers don't find too many fishbonic flaws with it first!
P.S. Yep, I know, it's not like there aren't already enough rule variations for pool (which [calum]'s links do a good job of explaining)!