League rules and bar rules compared.

The same eight-ball shot can win the game in one league and be a simple foul in another. Here is where the major rulebooks disagree, and what can and cannot be said about bar rules.

Wikipedia's eight-ball article notes that the APA, CPA, VNEA and BCA Pool League each have their own rulesets, slightly different from the WPA's and from each other. This page compares four of them on the points where they actually differ. It uses:

WPA: the Rules of Play effective 15 September 2025, read from a copy hosted by the Hong Kong Billiard Sports Control Council.
CSI: the Official Rules of CueSports International, used by the BCA Pool League (BCAPL) and USA Pool League. The document shows an effective date of 1 June 2023, although its file name contains "08122025."
APA: the American Poolplayers Association's official rules pages.
VNEA: a copy of the VNEA eight-ball league rules hosted by a third party. It is undated, so it may not be the current version.

Where a cell says "not documented," the source we read did not cover that point. It does not mean the league has no rule on it.

Eight-ball: the main differences

Situation	WPA	CSI (BCAPL, USAPL)	APA	VNEA
8 pocketed on a legal break	Not a win. Breaker spots the 8 and plays on, or breaks again (4.3e)	Not a win. Breaker spots the 8 and continues, or re-racks and breaks (2-4-1)	Wins, unless the breaker also fouls the cue ball, which loses	Wins in league play, unless the cue ball scratches on the same shot, which loses
Scratch or foul shooting at the 8, 8 stays up	Standard foul, ball in hand (4.8)	Ball in hand, not loss of game (2-9-2)	Scratching or knocking the cue ball off the table loses the game	Scratching with the 8 as your target loses the game
Groups after the break	Table stays open (4.3c)	Table stays open	If balls from only one group drop, that group is the breaker's; if both, table stays open	Table is always open after the break
Ball in hand after a foul on a legal break	Behind the head string (4.3h)	Anywhere on the table (2-3-4)	Behind the head string	Not documented
Calling shots	Every shot except the break (4.6)	Obvious shots need not be called; banks, kicks, combinations and non-incidental kisses or caroms must be (1-16)	The pocket for the 8 must be marked; see note below on other shots	Not documented
Accidentally moving an object ball	Standard foul (3.6)	"Cue ball fouls only": moving one object ball is a foul only if it affects the shot (1-33)	Listed fouls include touching or moving the cue ball outside ball in hand, and the cue ball hitting an accidentally moved ball	Not a foul unless it is the cue ball
Soft breaks	Not documented	Allowed if you tell your opponent first (2-3-2)	Not allowed; local management may penalize players who do not break hard	Not documented
Stalemate	Referee announces it, then three more turns each unless both players agree to skip them; breaker re-breaks (1.13, 4.11)	Declared when every possible shot would lose, or nothing significant changes over three innings each; replayed with the same breaker (2-11)	Both players agree; re-rack, original breaker breaks; no minimum number of turns	Not documented
Three consecutive fouls	Not used in eight-ball	Not used in eight-ball (1-22 lists other games only)	Not documented	Not documented

Notes on the table

APA calling. The APA pages we read require marking only the pocket for the 8. The phrase "slop counts" (meaning balls that drop count without being called) is often used to describe APA eight-ball, but our source for that wording is Dr. Dave Alciatore's forum summary, not an APA page, so we could not confirm it as APA's own language.
APA marking. The APA wants the 8's pocket marked with a coaster or another reasonable marker, and does not recommend chalk. The 8 touching the marker is not a foul. Failing to mark the pocket properly loses the game if your opponent calls it.
Other ways to lose in APA. Pocketing the 8 out of turn or knocking it off the table, pocketing it in the wrong pocket, pocketing it on the same shot as your last group ball, and pocketing it on a called cue-ball foul all lose. So does deliberately altering the path of the 8 or the cue ball to avoid a loss. Missing the 8 entirely without scratching is a foul with ball in hand, but not a loss.
Other ways to lose in CSI. CSI rule 2-10 lists illegally pocketing the 8, jumping it off the table (except on the break), pocketing it on the same shot as your last group ball, pocketing it on an uncalled shot that was not obvious, and committing certain disturbed-ball fouls while the 8 drops.

Nine-ball: the main differences

VNEA nine-ball was not covered by our sources, so this table compares three rulebooks.

Situation	WPA	CSI	APA
First contact on the break	Not specified in the rule we read	Must be the 1, or it is a foul (3-3)	Must be the 1, but missing it is not a foul
9 on the break	Wins, by our reading of rule 5.5	Wins on a legal break; spotted on a break foul (3-3-3)	Wins unless the breaker scratches; then spotted and the turn passes
Push out after the break	Allowed (5.4)	Allowed, if announced and acknowledged (3-4)	Not allowed in handicapped play; allowed in Masters
Three consecutive fouls	Loss of rack (5.8)	Loss of game (3-6)	Not documented

The APA pages also state that a foul on the nine-ball break gives the opponent ball in hand anywhere, and that APA handicapped nine-ball is scored in points: balls 1 to 8 are worth one each and the 9 is worth two.

Other APA rules worth knowing

Legal break. The APA break comes from behind the head string and must pocket a ball or drive at least four object balls to the rails, with the cue ball not touching a rail before reaching the rack. In eight-ball, the break must hit the head ball or a second-row ball first, but missing that is not a foul. An illegal break is re-racked by the non-breaker and broken again by the same player; if it also scratched, the opponent breaks the new rack.
Calling fouls. Only the shooter or the team captain may officially call a foul, and a foul not called before the next shot cannot be called later.
Combinations. On an open table, a combination may mix stripes and solids, but the 8 may not be the first ball contacted. If you miss your own ball but pocket an opponent's, you lose your turn and their ball is not spotted.
Equipment. Jump cues are allowed only in Masters divisions. A regular cue may be used for jump and masse shots anywhere in APA play, but may not be taken apart to shorten it. Laser devices, mechanical cues and training aids are banned; bridges and cue extenders are allowed.
Who breaks. The lag winner breaks the first game, and the winner of each game breaks the next. In-Play magazine's summary adds that the loser of the lag or of the previous game racks.
Handicaps. The Equalizer system has stronger players give games (eight-ball) or points (nine-ball) to weaker ones. A team's five players in an Open match may not total more than 23 skill levels. See leagues for more.

Bar rules and house rules

There is no single set of "bar rules." Wikipedia notes that casual players often follow house rules that differ by region and even between venues. Dr. Dave Alciatore's eight-ball flyer argues that the rules vary so widely because most players pick up the game by word of mouth. Because these rules are not written down in one place, we only report variations a source actually documents.

What Dr. Dave's flyer contrasts with WPA rules

The flyer sets WPA rules against common bar practice on four points: calling every shot, ball in hand anywhere after every foul (rather than only behind the head string), and the wrong-ball-first and no-rail-after-contact fouls. It points out that without penalties for those fouls, a player can nudge the cue ball a few inches and leave the opponent with nothing to shoot at, which the WPA penalties discourage.

Variations used in some leagues and tournaments

Dr. Dave's rules summary lists these as variations found in some leagues and tournaments, and says some of them come mainly from coin-operated tables:

An 8 on the break wins, or loses if the cue ball scratches.
A scratch or foul on a missed 8 loses.
Balls pocketed by accident are spotted when the called ball misses.
A 9 on the break is spotted instead of winning.
An uncalled 9 is spotted.
Balls knocked off the table are spotted.
Only cue-ball fouls count.

In a forum discussion, Dr. Dave describes "cue ball fouls only" as a league rule (also used in some tournaments) and not part of the official WPA rules. Another poster in that thread says ball in hand behind the head string after a scratch is the more common league rule where they play.

What we could not confirm

Other bar rules are often mentioned, such as two shots after a foul, "last pocket" eight-ball, and having to call kisses. We did not find a rulebook-quality source for any of these, so we do not describe how they work. One related point is documented: Blackball, the British form of eight-ball, does give two shots after some fouls, but it is an official WPA discipline with its own section of the rulebook, not a bar rule.

A league player's blog comparing APA and BCA rules summarizes the differences much as the table above does: groups by what drops on the break versus an open table, calling the pocket or not, a scratch on the 8 losing versus giving ball in hand, and a legal 8 on the break winning versus being spotted. It is a blog rather than a rulebook, so we use it only as a cross-check.

Before you play

The practical advice that follows from all of this is simple: before the first break, agree on which rules you are playing. In a league, that means the league's own rulebook. Against a stranger in a bar, settle at least the 8 on the break, a scratch on the 8, ball in hand placement, and whether shots must be called. For conduct at the table, see etiquette.

Sources