Casino War: Rules, Payouts, House Edge and Origin
Summary
Casino War is a banking card game in which the player and the dealer each receive one card and the higher rank wins. It is played against the house with a standard deck shoe, most commonly six decks, and has one decision point: what to do when the two cards tie. Under six deck rules in which the player always goes to war, the house edge on the main wager is 2.88%. The optional Tie bet, at 10 to 1, carries an edge of 18.65%.
| Field | Value |
|---|---|
| Category | Other Card Games |
| Decks | Six in the reference ruleset; one to eight decks also documented below |
| Player decisions | One, and only after a tie: go to war or surrender |
| Main wager edge, six decks, always go to war | 2.88% |
| Tie bet edge, six decks, 10 to 1 | 18.65% |
| Last verified | 29 September 2026 (derived figures, recalculated for this entry) |
Rules
- The player places a main wager and, optionally, a Tie bet.
- The dealer gives one card face up to the player and one to the house.
- Cards rank as in poker, with Ace high and 2 low. Suits have no rank.
- If the player's card is higher, the main wager wins even money. If the dealer's card is higher, it loses.
- If the cards are of equal rank, the player must choose. Surrender forfeits half of the main wager and ends the round. Going to war means placing a second wager equal to the first, after which the dealer burns three cards and deals one new card to the player and one to the house.
- In the war, if the player's card is higher or equal, the raise wins even money and the original wager pushes. If the dealer's card is higher, both wagers lose.
Rule 6 is the reference ruleset used for the edge figures below. A common alternative pays a bonus when the war itself ties, described under Variant Differences.
Payouts
| Outcome | Main wager | Raise | Net result per unit wagered initially |
|---|---|---|---|
| Player card higher | Wins 1 to 1 | None placed | Plus 1 |
| Dealer card higher | Loses | None placed | Minus 1 |
| Tie, player surrenders | Half lost | None placed | Minus 0.5 |
| Tie, war won or tied | Push | Wins 1 to 1 | Plus 1 |
| Tie, war lost | Loses | Loses | Minus 2 |
| Tie bet, initial cards tie | Settled separately | None placed | Tie bet pays 10 to 1 |
House Edge
All figures below are derived from card counts, not quoted from an operator. They assume a freshly shuffled shoe for each round, so a continuous shuffler is the closest real equivalent.
Derivation, six decks
A six deck shoe holds 312 cards, 24 of each rank. After the player's card is dealt, 23 of the remaining 311 cards match it, so the probability of an initial tie is 23/311, or 7.395%.
Outside a tie, the game is symmetric: the player and the dealer are equally likely to hold the higher card, so non tie rounds contribute nothing to the edge. The entire house advantage comes from the tie.
After a tie, two cards of one rank are gone. The probability that the war cards tie again works out to 7.397%. The player wins or ties the war about 53.70% of the time and loses about 46.30%. Going to war is worth 0.537 × 1 minus 0.463 × 2 = minus 0.389 units per tie. Multiplying by the 7.395% chance of a tie gives minus 0.0288, a house edge of 2.88%.
Surrendering instead costs exactly 0.5 units per tie, so 0.07395 × 0.5 gives 3.70%. Going to war therefore has a lower edge than surrendering under these rules.
The Tie bet wins 10 units with probability 7.395% and loses 1 unit otherwise: 0.7395 minus 0.9261 = minus 0.1865, an edge of 18.65%.
Edge by number of decks
| Decks | Initial tie probability | Main wager, always war | Main wager, always surrender | Tie bet at 10 to 1 |
|---|---|---|---|---|
| 1 | 5.882% | 2.42% | 2.94% | 35.29% |
| 2 | 6.796% | 2.70% | 3.40% | 25.24% |
| 6 | 7.395% | 2.88% | 3.70% | 18.65% |
| 8 | 7.470% | 2.90% | 3.73% | 17.83% |
Last verified 29 September 2026. The direction of the two effects is opposite. More decks make ties more frequent, which slightly raises the main wager edge but sharply lowers the Tie bet edge, because a 10 to 1 payout is priced against tie frequency.
Variant Differences
Tie bonus on the war. Some tables pay the original wager as well as the raise when the war cards themselves tie, instead of pushing the original. Under six decks and always going to war, this lowers the main wager edge from 2.88% to 2.33%. Across the deck counts above, the bonus version runs from 2.06% with one deck to 2.34% with eight.
Tie bet payout. The Tie bet edge depends entirely on the payout offered. The 10 to 1 figure is the reference here. Any lower payout on the same shoe raises the edge further.
Surrender availability. Surrender is part of the reference ruleset, but under every deck count in the table it produces a higher edge than going to war, so a table that removes surrender does not raise the cost for a player who always goes to war.
Origin
Casino War takes its structure from War, the two player card game in which each player turns over a card and the higher rank takes both. The casino version adds a house bank, a multi deck shoe, the surrender option and the side bet. No inventor, first venue or introduction date is recorded in the sources used for this entry, and none is asserted here. Claims found elsewhere that attribute the game to a specific person or year should be treated as unverified.
Responsible Gambling
Casino War rounds resolve in seconds with almost no decisions, so the 2.88% edge is applied very quickly and the Tie bet's 18.65% edge is the costliest option on the layout. The legal age to gamble in Canada is 19 in most provinces and 18 in Alberta, Manitoba and Quebec, and play should only take place with operators licensed in the player's province. In Ontario, ConnexOntario offers free, confidential support around the clock at 1 866 531 2600.