CS2 roulette: T, CT and the bonus slot explained
How the 15-slot T, CT and bonus wheel works, what the 2× and 14× payouts mean for your odds, how it compares with casino roulette and how to check a round.
Fact-checked 18 October 2026 · 5 sourcesCS2 roulette is a wheel of 15 slots: seven T, seven CT and one bonus. T and CT pay 2×, the bonus pays 14×, and one spin settles every bet in the round. Those three numbers fix the odds and the house edge, and they explain why this wheel costs more per bet than the one in a casino.
The wheel
The slots are numbered 0 to 14. Slot 0 is the bonus, 1 to 7 are T and 8 to 14 are CT. On the wheel itself T and CT alternate all the way round, with the bonus sitting between the last CT slot and the first T slot.
You pick T, CT or the bonus before the spin, and everyone in the round shares the same result. That result is slot = floor(float × 15), where the float is a number between 0 and 1 taken from the round's hash (more on that below). Every slot has the same 1-in-15 chance; what differs is how many slots each bet covers.
Odds, payouts and the edge
| Bet | Slots | Chance | Pays | Average return per coin | |---|--:|--:|--:|--:| | T | 7 | 46.67% | 2× | 0.933 | | CT | 7 | 46.67% | 2× | 0.933 | | Bonus | 1 | 6.67% | 14× | 0.933 |
Each return is chance × payout: 7/15 × 2 = 14/15 for T or CT, and 1/15 × 14 = 14/15 for the bonus. Every bet hands back 14 coins for each 15 staked on average, so these payouts carry a house edge of 1/15, about 6.67%, whichever side you pick. The game page shows the edge next to the bet limits.
It's easy to see where the edge comes from. A fair 2× bet would need to win half the time, but T and CT each win 7 times in 15, because the bonus slot belongs to neither of them. For the bonus to be a fair bet it would have to pay 15×; it pays 14×. Over many rounds, 100 coins of bets lose about 6.67 coins on average, however they're spread across the colours. House edge and RTP explains how that average plays out over time.
No combination of bets escapes it. Put 1 coin on T and 1 on CT and you get your 2 coins back in 14 rounds out of 15, then lose both when the bonus lands: an average loss of 2/15 of a coin per round on 2 staked, the same 6.67%. Put 7 on T, 7 on CT and 1 on the bonus, and every possible slot pays back exactly 14 of your 15 coins.
Compared with a casino wheel
Casino roulette in most of the world uses a single-zero wheel: 37 pockets, the numbers 1 to 36 plus a green zero. François and Louis Blanc introduced it at Bad Homburg in 1843 to compete with casinos whose wheels had both a zero and a double zero. A bet on red or black pays even money, the same 2× return as T or CT, but it wins 18 times in 37.
| Wheel | House slots | Total slots | Even-money win chance | House edge | |---|--:|--:|--:|--:| | T/CT wheel | 1 | 15 | 46.67% | 6.67% | | Single zero | 1 | 37 | 48.65% | 2.70% | | Double zero | 2 | 38 | 47.37% | 5.26% |
The difference is the size of the wheel. On a single-zero wheel the zero is one pocket in 37, so it takes 1/37 of every bet. On a 15-slot wheel the bonus is one slot in 15 and takes 1/15, about two and a half times as much. The small wheel gives you a simpler board and a 14× slot in return; it doesn't give you better odds.
Streaks mean nothing
Each round's result comes from a fresh hash, so the wheel has no memory. After five CT in a row, the next round lands on T with the same 7-in-15 chance as any other. Five T in a row from a given starting point is a 2.2% shot, which sounds rare, but in 100 rounds there's about a 71% chance of seeing a run of five or more T somewhere.
The bonus works the same way. It lands once every 15 rounds on average, yet there's a 12.6% chance of going 30 rounds without one and a 4.5% chance of going 45. It's never due. In 1913 a Monte Carlo roulette wheel came up black 26 times in a row, and gamblers lost millions of francs betting that red had to follow; the episode gave the gambler's fallacy another of its names, the Monte Carlo fallacy. The gambler's fallacy goes into why streaks fool people, and Martingale and other betting systems shows why raising stakes to chase a late bonus only pushes more coins through the same edge.
How a round is verified
Roulette uses the same scheme as the other shared games. The game has a hash chain: a secret hashed with SHA-256 over and over, with the final hash, the terminal, published before the first round. Rounds use the chain backwards, so each round's seed hashes to the previous round's seed and none can be swapped later. Each seed is then mixed with a drand beacon, a public random value that's published only after betting closes, so nobody knows the result while bets are open:
round hash = HMAC-SHA256(seed, drand randomness)
The first four bytes of the round hash become the float. A round hash starting 6b2f10c4, for example, gives the bytes 107, 47, 16 and 196, so the float is 107/256 + 47/256² + 16/256³ + 196/256⁴ = 0.41869. Times 15 that's 6.28, which rounds down to slot 6: T.
Round pages run this check in your browser, and the provably fair page explains each step. Drand explained covers why the beacon can't be known in advance. A verified round shows the slot wasn't picked after the bets came in. It doesn't change the 1/15 the house keeps on average, which is the number to weigh before playing Roulette.
