Craps: rules, bets and the real odds

Craps is played with two six-sided dice. One player — the shooter — throws them, and everyone at the table bets on the outcome. Because every result is just the sum of two dice, the whole game rests on one probability table, which makes craps unusually easy to play well once you understand it.

The dice and how you roll

The shooter throws both dice so they hit the far wall of the table (a rule that keeps throws honest). Play happens in rounds:

• The come-out roll starts a round. If it lands a 7 or 11, Pass Line bets win immediately (a “natural”). If it lands 2, 3 or 12, that is “craps” and Pass Line bets lose.
• Any other number — 4, 5, 6, 8, 9 or 10 — becomes the point. The shooter keeps rolling until they either roll the point again (Pass wins) or roll a 7 first (Pass loses, and the dice pass to a new shooter).

The 2d6 probabilities — the heart of the game

There are 36 equally likely combinations of two dice. Seven is the most common sum, appearing 6 times in 36 — which is exactly why a 7 both wins the come-out and ends a point round.

Notice the symmetry: 6 and 8 are the likeliest points, 4 and 10 the hardest. That single fact drives almost every good decision at the table. (Want to see it live? Roll two dice a few dozen times and count the sevens.)

The main bets and how to play

• Pass Line — bet with the shooter. Wins on a come-out 7/11, loses on 2/3/12, otherwise waits for the point. House edge about 1.41% — one of the best bets in any casino.
• Don’t Pass — the mirror image, betting the shooter fails. Slightly better still at about 1.36% (12 is a push, not a win).
• Come / Don’t Come — exactly like Pass/Don’t Pass but started on any roll after a point is set, letting you back several numbers at once with the same low edge.
• Free odds — once a point is set, you can back your Pass or Come bet with an additional “odds” wager that pays at true mathematical odds and carries a 0% house edge. Taking maximum odds is the single best move in craps.

The winning strategy is simple to state: Pass (or Don’t Pass) plus maximum free odds, and nothing else. Backing 6 and 8 through Place bets is a reasonable extra, but the odds bet is unbeatable value because the house takes no cut of it.

Common mistakes

• Chasing proposition bets. The one-roll bets in the centre of the layout — Any 7, Hardways, the “Yo” 11 — look exciting but carry house edges from roughly 9% up to about 16%. They drain bankrolls fast.
• Skipping the odds bet. Many players make a Pass bet and never back it with odds — leaving the only 0% wager in the building on the table.
• Believing the dice are “due”. Every roll is independent. A run of numbers with no 7 does not make a 7 more likely on the next throw; the probability is always 6/36.
• Betting the Field for the long haul. The Field looks generous (it covers seven numbers) but the common house edge is around 5.5% because the likeliest sums — 5, 6, 7, 8 — mostly lose.

Want another two-dice game where probability rules? See how the same table drives resource production in our Catan guide.