What is the baulk-line crossing rule in billiards?
A · Advanced · Playing the game · 3 of 5Where an event uses it, the baulk-line crossing rule makes the cue-ball cross the baulk-line into baulk, as part of a legal stroke, once in every hundred points of a break. The crossing must come between 80 and 100. The referee warns at 80 and confirms when the line has been crossed. Failing to cross is a foul.
How it works
- When it applies: only in events that use it.
- Once in each hundred: between 80 and 100 points of every 100 in a break.
- Into baulk: the cue-ball must cross into baulk, down the table.
- Resting on the line: has not crossed.
- Coming back: the cue-ball does not have to return out of baulk.
- "Baulk-line warning at 80": called after the stroke that takes the break to 80 or more.
- "Baulk-line crossed": called when the referee is satisfied.
- A late warning: the player then has 20 points from the warning to cross.
- From in-hand or within baulk: the cue-ball must first leave baulk and then cross back.
- Not crossing in time: a foul, unless the break ends first with a non-scoring stroke.
The glossary has the baulk-line crossing, the baulk, the break, the cue-ball, the foul and the referee.
Tricky cases
Does the rule apply in every billiards match?
No. It applies only in events where the baulk-line crossing rule is used.
A break reaches 102 without a crossing, then the player misses. Is that a foul?
No. The failure is a foul unless the turn ends with a non-scoring stroke.
The cue-ball stops exactly on the baulk-line. Has it crossed?
No. Resting centrally on the baulk-line means it has not crossed.
The referee forgets the warning until the break is 90. What then?
The player must cross within 20 points of the warning, so by 110. The next warning is still due at 180.
Why the rule exists
Top players could keep all three balls near the top of the table and score there almost without end. The crossing rule forces the cue-ball down the table every hundred points, which breaks up that pattern and asks for a wider range of play.
Where it differs
| Where | What changes | Source |
|---|---|---|
| Events using the rule | Cross between 80 and 100 of every 100 | WPBSA Billiards 3.8 |
| Events not using it | No crossing needed | WPBSA Billiards 3.8 |
| Failure | Foul | WPBSA Billiards 3.8(h); 3.15(t) |
| Late warning | 20 points from the warning | WPBSA Billiards 3.8(e) |
From the rule book
World Professional Billiards and Snooker Association, Official Rules of the Games of Snooker and English Billiards (May 2022 update), English Billiards part, English Billiards Section 3 Rules 8 and 15(t). Checked 14 October 2026. Official document: the association's rule book, which covers snooker and English billiards together.