Games · Craps
Craps: roll the dice and see the edge
Craps looks like the most intimidating table in the casino — but the bets that matter are simple, and the math is unusually friendly if you stick to them. Roll the dice for free, take the pass line with free odds (the only 0% house-edge bet anywhere), and watch exactly why the flashy center-table bets cost the most.
Educational simulation — fun credits only, no real money. The house edge is real on every bet except free odds (0%): the pass line is 1.41%, place 4/10 is 6.67%, the field 5.56%. The longer you play, the more the math wins.
Build your strategy
Stack several bets and run a whole table session — combined net, total action, and what's still on the felt at the end. A multi-bet table has no single house edge, so this is a session simulation, not an edge estimate.
- No bets yet — add one above.
Educational simulation — fun credits only, no real money. The observed edge wobbles over a short run; over many cycles it tends toward the exact long-run expectation, but random variation never fully disappears.
| Bet | Pays | Win chance | House edge (per wager) | Loss / $100 |
|---|---|---|---|---|
| Don't Pass / Don't Comebar 12 — 12 pushes | 1:1 | 47.93% | $1.36 | |
| Pass Line / Comethe line bet | 1:1 | 49.29% | $1.41 | |
| Place 6 / 8rolls before a 7 | 7:6 | 45.45% | $1.52 | |
| Place 5 / 9rolls before a 7 | 7:5 | 40.00% | $4.00 | |
| Fieldone-roll: 2 3 4 9 10 11 12 | 1:1 · 2&12 dbl | 44.44% | $5.56 | |
| Place 4 / 10rolls before a 7 | 9:5 | 33.33% | $6.67 | |
| Free odds (take / lay)true odds behind a line/come bet | true | — | $0.00 |
The odds effect — free odds drag your edge toward zero
A pass line alone is 1.41%. Free odds pay true odds (0% edge), so backing the line spreads that same expected loss over far more action — the combined edge on everything you wager falls fast:
Edge on total action (flat bet + the odds you'd wager once a point is set). With 3-4-5× odds the pass line's effective edge is just 0.37% — the cheapest action in the casino. Try it live in the Play and Simulate tabs.
The field's two variants
- 2 & 12 both pay 2:1 (common)5.56%
- 12 pays 3:1 (better tables)2.78%
The field looks friendly — it wins on seven of eleven totals — but it loses on 5, 6, 7, 8, which are the most common rolls. Even the better 3:1 version trails the line bets.
Why place 6/8 beats place 4/10
- Place 6 / 8 — pays 7:61.52%
- Place 5 / 9 — pays 7:54.00%
- Place 4 / 10 — pays 9:56.67%
6 and 8 are the easiest numbers to roll before a 7, so their place bet is priced closest to fair. The 4 and 10 are the hardest — and the casino's 9:5 payout shorts them the most.
How this simulation works
- Rules modeled
- Two-die craps with the come-out → point state machine. Core bets: Pass / Don't Pass (bar 12), Come / Don't Come, Free Odds (take and lay), Place (4,5,6,8,9,10), and the Field. Free-odds cap configurable (default 3-4-5×); field default pays 2:1 on both 2 and 12 (a 3:1-on-12 variant is available). Stakes are whole dollars, with the traditional bet units (place 6/8 in $6, 5/9 & 4/10 in $5, odds sized for an exact payout).
- Assumptions
- Two fair, independent dice. Fun credits only, no real money. The 'house edge' shown is the exact figure per initial wager (the don't side includes the bar-12 push). Free odds are true odds — 0% edge — so the combined edge shown for a line bet plus odds is measured on total action and falls as you add odds. Come odds and place bets are off on the come-out by default. Over many rolls the observed edge tends toward the exact figure; random variation always remains over any finite session.
- Mathematical basis
- Odds and edges come from an exact analytic solver (exact bigint rationals: one-roll enumeration for the field, per-resolution ratios for place bets, the come-out distribution plus a per-point geometric series for line/come bets, true odds for free odds), the displayed source of truth; the Monte-Carlo simulator only validates against it. Reference edges: pass/come 1.41%, don't 1.36%, place 6/8 1.52% · 5/9 4.00% · 4/10 6.67%, field 5.56% (2:1) / 2.78% (3:1 on 12), free odds 0%, pass + 3-4-5× odds ≈ 0.37% on total action.
- Engine version
- craps engine 1.0
- Validation
- Unit-tested (every bet's edge, the per-initial-wager vs per-resolution distinction, the full come-out→point lifecycle with come bets traveling independently, the working/off matrix, place stay-up, the stake-aware combined-odds identity across every cap, invariants, seeded reproducibility, and SE-scaled convergence).
- Last reviewed
- Independently reviewed for math and code correctness; every reported finding was addressed and regression-tested. Last reviewed 2026-06-24 (1 review passes).