- Rules modeled
- Standard 6-deck Casino War. Player and dealer each get one card (ace high; suit is irrelevant to the game); the higher card wins even money. On a tie the player either surrenders (forfeits half the ante) or goes to war: raise an amount equal to the ante, the dealer burns 3 cards and deals one more to each; the player's card winning OR tying beats the dealer, paying even money on the raise while the original ante pushes (net +1 ante); a loss forfeits both (net −2 antes). Optional Tie side bet pays 10:1 when the first two cards tie. Stakes are fun credits in integer cents.
- Assumptions
- Hands are independent (a freshly shuffled shoe each round). Ace is always high; suits never break a tie; a tie is a tie. No side rules (no war-tie bonus). This models the common US 6-deck rules; other deck counts shift the edge slightly (shown in the Odds tab). Fun credits only, no real money.
- Mathematical basis
- Every figure is exact and closed-form, not simulated. P(tie) = (R−1)/(N−1) for R = 24 cards per rank and N = 312 cards; the go-to-war, surrender, and Tie-bet edges follow directly (2.88% / 3.70% / 18.65% at 6 decks; the standard published figures). The Play and Lab draw from the same engine; the Lab's Monte-Carlo only validates the exact edges, never redefines them.
- Engine version
- casino-war engine 1.0
- Validation
- 14 unit tests: exact edges vs the published figures (war 2.88% / surrender 3.70% / Tie bet 18.65% and P(tie)=23/311), the war payout mechanic (win +1 / lose −2 / ties to the player), surrender (−½), the 10:1 Tie bet, deck-count sensitivity, seeded determinism, and a 200,000-hand convergence to 2.88%.
- Last reviewed
- Verified by exact unit tests against the published house edges (the math is closed-form arithmetic, not a solver); no separate independent-review gate was required for this engine. Last reviewed 2026-06-30.
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