It's a tie! Double your bet and go to war, or surrender half.
Free game, fun credits only, no real money. Optimal play: always go to war, never surrender, never take the Tie bet.
settings changed, re-run
n/aobserved edge
2.88%exact (go to war)
n/aties β war
The dashed gold line is the exact house edge, 2.88%. Short runs swing
wildly; the more hands you play, the tighter the observed edge hugs it; the house edge is a long-run certainty, not
a per-hand one. For contrast: surrendering every tie is 3.70%, and the Tie side bet
is a brutal 18.65%.
Casino War is the simplest game on the floor; one card each, higher wins. And yet the exact math,
below, shows it still tilts to the house. Every figure is closed-form (no simulation) for a 6-deck shoe.
7.40%chance of a tie (23 in 311)
46.30%you win outright (same for the dealer)
What each bet really costs
Bet / choice
House edge
Verdict
Go to war (on a tie)
2.88%
Optimal play
Surrender (on a tie)
3.70%
Costs 0.82% more, never do it
Tie side bet (10:1)
18.65%
Sucker bet: ~6Γ the main edge
Why it works out this way
No tie (about 93% of hands): a coin flip: you win or lose one unit, and it
washes out to zero on its own.
A tie (7.40%): here's the catch. Go to war and you must double your bet, but a
win only pays even money on the raise; the original ante just pushes. Win 54%βish of
wars (ties go to you) for +1 unit; lose the rest for β2 units. That asymmetry is the entire house edge.
Surrendering hands back half your ante every tie: a flat 3.70% drag, worse than
the 2.88% from always warring. So the rule is simple: always go to war, never surrender.
The Tie bet pays 10:1 but a tie hits only 7.40% of the time; a fair payout would be about
12.5:1. That gap is a brutal 18.65% edge. Skip it.
Does the deck count matter?
A little: more decks means a slightly higher tie chance, so a slightly higher edge. Still tiny either way:
Decks
Go-to-war house edge
1
2.42%
2
2.70%
6
2.88%
8
2.90%
The exact odds of Casino War, even the simplest game keeps 2.88%. Fun credits only, no real money.