How We Check the Odds

Nothing here is rigged. Every game plays by real casino rules, and the house keeps exactly what those rules give it, no more. Here's how we make sure of that, and the numbers that show it.

Our promise

• The cards and dice are random, and nothing looks at your bets or your balance.
• Every bet pays what the table says it pays.
• The house edge is whatever the real rules produce. We don't tilt it, even though it's only play money.

Where the cards and dice come from

Every shuffle and every roll uses your browser's cryptographic random number source, the same kind that protects passwords and payments. Blackjack and War Blackjack deal from a real six-deck shoe: all 312 cards shuffled together, a card burned, and a cut card about three-quarters of the way through. Cards come off the shoe in order, just like a casino, which is why card counting works here in principle.

In Bubble Craps the result of each roll is decided first, and the tumbling dice then show that result. The animation never changes what was rolled.

Step 1: the rules on their own

Each game's rules were written and tested before there was any screen to look at. Hundreds of tests deal a stacked deck or set the dice to a fixed roll, one rule at a time, and check the exact payout to the cent. To make sure the checks themselves work, we break the game on purpose, for example by paying a blackjack 6 to 5, and make sure the checks catch it.

Step 2: ten million rounds

A small bug in a payout is invisible when you play, but not over millions of rounds. So each game is played ten million times by a computer following the rules exactly, and what each bet actually kept is compared with what it should keep.

Every result lands inside the small margin that chance allows over ten million rounds, for every bet checked in all three games, so every check passes. (A slightly negative figure means players came out a hair ahead on a bet with no house edge, which chance allows.) A payout that's even slightly wrong, like a blackjack paid 6 to 5, would show up here straight away.

Step 3: the exact math

Where the answer can be worked out exactly, we work it out rather than trusting the simulation alone:

• Blackjack: the value of every play, for every hand against every dealer card, calculated exactly. Played by our strategy chart the game keeps 0.58%, and every one of the chart's 540 cells is checked to be the best play.
• War Blackjack: with six decks, a War bet ties (and so loses) exactly 23 times in 311, which is where its 7.40% comes from.
• Bubble Craps: every bet worked out as an exact fraction over the 36 ways two dice can land. The Pass Line keeps exactly 7/495, or 1.41%.

What "house edge" means

The house edge is the share of your bets the game keeps over a very long run. A 1.41% edge means about $1.41 of every $100 you bet, on average, over thousands of rounds. In any one session you can win or lose far more than that, which is what makes it a game. No betting system changes it.

Every game's house edge

Questions

Does the game make me lose when I'm winning?

No. The random source doesn't know your balance, your bets or your streak. Every hand and every roll is independent.

Why does the house win at all if it's play money?

Because that's how the real games work. A free table that paid better than a casino would teach you the wrong lessons about real odds.

Can I check this myself?

Play long enough and your results will drift toward the numbers above. Our Learn modes also explain each bet and, in Blackjack, show the best play for every hand.

Play money only. No real wagering, no prizes, nothing to buy.