How roulette works
Roulette involves placing a bet on one or more outcomes before a ball settles into a numbered pocket. Different bet categories cover different numbers of pockets and pay accordingly. A winning color or number on one spin does not influence an independent next spin.
European and American wheels are not equivalent
A European wheel has 37 pockets including a single zero; a traditional American wheel has 38 pockets including zero and double zero. For a straight-up single-number bet, the probability is 1/37 on a European wheel and 1/38 on a traditional American wheel. Those are mathematical examples, not claims about any particular platform’s live selection.
Practical bet-category worksheet
| Bet type | Typical coverage | What to know |
|---|---|---|
| Straight-up | One number | Less frequent wins, higher listed payout |
| Split | Two adjacent numbers | Requires allowed layout placement |
| Red/black | 18 numbered pockets | Zero means it is not a 50/50 bet |
| Dozens | 12 numbered pockets | Still loses on zero |
Why betting systems do not eliminate the edge
Increasing a stake after losses does not change the odds of the next independent spin. Systems like Martingale can increase exposure quickly and run into limits. Assess the game rules and your session limits instead of trusting a “guaranteed roulette strategy”.
Find related guidance
Compare roulette with the hand decisions in blackjack. The games guide explains other formats and currencies.