Casino War
The simplest card game · highest card wins
History
Casino War is based directly on the children’s card game "War", known around the world for decades. The casino version was developed and trademarked by a United States company in the 1990s. It is one of the simplest casino games — created to attract players who find more complex table games intimidating.
Casino War is a good example of how casinos turn a familiar game into a product. The children’s game of "War" is perfectly fair — both players have an equal chance of winning. The casino adds one rule (the partial payout on a war win) and thereby creates a house edge practically from nothing. The simplicity is the selling point: anyone can play immediately.
Where it is played today
Casino War is common in United States casinos as a beginner-oriented table, and it also appears at online casinos. It has never been a high-stakes game — its appeal is its simplicity: no rules to learn, just the highest card wins.
Rules
Both you and the dealer get one card. The higher card wins (ace is highest). A win pays 1:1. If the cards are equal in value, it is a "war": you can either surrender and get half your bet back, or go to war by placing a second bet. In a war new cards are dealt; if you win, you get both bets back plus the win on your original.
Odds & the maths
The house edge of Casino War is about 2.9% if you always go to war on a tie (surrendering is mathematically the worse choice, about 3.7% house edge). The edge comes from the fact that when you win a war, you are paid only on your original bet, not the second. The lesson: the game feels like a 50/50 situation, but the handling of the tie tilts it to the house.
The probability of a tie is about 7.4% on every deal. When it hits, you have two options, and their mathematical difference is an important lesson: surrendering costs you half the bet for certain, going to war gives a roughly 50/50 chance to get the whole bet back plus a win. In the long run going to war is slightly better — even though it feels riskier.
| Outcome | Pays | Probability |
|---|---|---|
| Your card is higher | 1:1 | ~44.1% |
| Dealer card is higher | — | ~44.1% |
| Tie (war) | war or surrender | ~7.4% |
| Whole game (always to war) | — | house edge ~2.9% |
The house edge comes entirely from the handling of the tie: when you win a war, you are paid only on your original bet. Surrendering is mathematically the worse choice versus going to war.
Beginner’s guide
This is the easiest possible casino game to start with: no strategy, no rules. Set a bet, press Deal. If a war happens, the correct choice is almost always to go to war, not surrender — even though it feels riskier. Use this game to understand how even a tiny rule (the partial payout on a war win) creates a house edge in an otherwise fair game.