European roulette has 37 pockets: the numbers 1 to 36, half red and half black, plus a single green zero. Put chips anywhere on the layout, and whatever the ball lands on pays. Everyone at the table shares one wheel.

• -Pick a chip amount, then click the layout to place it.
• -The first chip on the table starts a 10 second countdown. When it runs out, the wheel spins for everyone, or sooner once everyone with chips down has pressed Spin.
• -Right-click a bet (or hold it on a phone) to take just that bet back.
• -You can back as many spots as you like in one spin.
• -Undo takes back your last chip; Clear takes back all of them.
• -Rebet repeats last round's bets; 2x doubles what you have down.

A winning bet returns your stake plus the odds, so a single number hands back 36 times the chip you put on it.

Zero is not red, black, odd, even, high or low, and it sits in no column or dozen. So every one of those bets loses when zero comes up - that single pocket is the entire house edge.

A single number pays 35 to 1 when there are 37 pockets, which is the same story told another way: the true odds are 36 to 1.

The result is an edge of exactly 1 in 37, or 2.70%, on every bet the table offers. American wheels add a second zero and double it to 5.26%, which is why single-zero tables are the ones to play.

Every bet carries the same 2.70% edge, so no combination of them is better than any other. What you are really choosing is how volatile you want the ride to be.

• -Even-money bets win just under half the time and pay small.
• -A single number wins about 1 spin in 37 and pays 35 to 1.
• -Covering more spots lowers your swings but also your ceiling - it does not improve the edge.
• -Spins are independent. A run of reds tells you nothing about the next spin.
• -Doubling after a loss, the Martingale, does not change the edge. It just trades many small wins for the occasional very large loss.