Most kids have played “War” with cards at one point or another in their young lives. Casinos have adapted the simple game for the entertainment of people who dislike complex rules. The dealer usually uses a six-deck shoe, issuing a card to a player after the bet is placed. Then a card is dealt to the dealer. The higher ranked card wins.

If the ranks are the same, the player can surrender, losing half the bet. Alternatively, the player can “go to war.” In that case, the player doubles his bet. The dealer burns three cards and then issues one to the player and one to himself (or herself). The higher card wins. If that is the player’s, then the war bet is paid at even money and the original debt is considered a push (tie). Some casinos pay a “bonus” of even money on the original bet, instead of calling it a push.

If the dealer wins the war showdown, the player loses both the original bet and the war bet. A tie the second time around results (in most places) in a win of both bets for the player.

A side bet on whether the war will result in a tie is available. The house edge on the bet varies from 18% to 35% depending on the number of decks used, and assuming a payout of 10 to 1.

On the head-to-head aspect of the game, both the player and the house have the same chance of winning (46.3%), assuming a six-deck shoe. The house advantage comes from winning double from the player in case of a tie, but only paying one-and-a-half bets to the player if he or she wins in case of a tie. This discrepancy gives the house a 2.88% edge in the case of a six-deck game. It goes down to 2.42% in a one-deck game. If the house pays a bonus on the second tie (which costs it one-half bet), then the edge drops to around 2.33% for a six-deck game and 2.06% for a one-deck game. The house advantage in the case of surrender is always a bit higher, so it makes sense never to surrender.