Game Contribution to Wagering Requirements: Why 10% Costs More Than 100%
Every casino bonus has two numbers attached to it, and the smaller one does more damage. The wagering multiplier is capped in Great Britain; the rate at which each game counts towards that wagering is not. This guide works out what the second number actually costs, in pounds, on the games players reach for when they want to clear a bonus cheaply.
The short answer. A game that contributes 10% does not make your wagering ten per cent harder — it makes it ten times harder. A 10x requirement on a £100 bonus is £1,000 of slot stakes or £10,000 of blackjack stakes. That is an effective requirement of 100x on the game people choose because it has a low house edge, and it is why the low-edge game is usually the more expensive way to clear a bonus.
The cap limits the multiplier, not the weighting
Since January 2026 the wagering requirement attached to a bonus at a Gambling Commission-licensed operator is capped at 10 times the bonus amount, which we cover in detail in our guide to the UK 10x wagering cap. That cap does exactly what it says: it stops an operator asking for 35x or 50x turnover before a bonus can be withdrawn.
What it does not touch is how much each game counts towards the requirement. Contribution rates are set in each operator’s own bonus terms, and they are typically 100% on slots, 10% on table games, and 0% — excluded entirely — on a list that often includes live dealer tables, progressive jackpot slots and any game with a hold or bonus-buy feature. Two players with the same £100 bonus and the same 10x requirement can therefore face £1,000 and £10,000 of turnover respectively, purely on the basis of which tab they open.
The arithmetic is a single division. Divide the wagering requirement by the contribution rate and you get the real requirement in stakes:
Actual stakes needed = (bonus × multiplier) ÷ contribution rate
£100 × 10 ÷ 0.10 = £10,000
What each game actually costs on a £100 bonus at 10x
The cost of clearing a bonus is not the turnover, it is the money the house edge takes out of that turnover along the way. Expected loss is stakes multiplied by house edge, and house edge is simply 100% minus the return to player. The table below runs both steps for a £100 bonus with a 10x requirement — £1,000 of contributing turnover — at typical UK contribution rates.
| Game | RTP | Edge | Counts | Stakes needed | Expected cost | Bonus net of cost |
|---|---|---|---|---|---|---|
| Slots | 96.0% | 4.00% | 100% | £1,000 | £40 | £60 |
| Video poker (full pay) | 99.5% | 0.50% | 10% | £10,000 | £50 | £50 |
| Blackjack (basic strategy) | 99.5% | 0.50% | 10% | £10,000 | £50 | £50 |
| Live blackjack | 99.4% | 0.60% | 10% | £10,000 | £60 | £40 |
| Baccarat (banker) | 98.94% | 1.06% | 10% | £10,000 | £106 | −£6 |
| European roulette | 97.3% | 2.70% | 10% | £10,000 | £270 | −£170 |
Read the last column rather than the third. Blackjack has one eightieth of the house edge of a typical slot and still costs more to clear the same bonus, because the 10% weighting forces ten times the turnover through it. Roulette turns a £100 bonus into an expected £170 loss. The game most players would name as the “safe” way to work through wagering is the one that destroys the value of the offer.
These are expected values over the full requirement, not predictions of any one session; real results swing widely around them, more so on slots than on blackjack. They also assume you are allowed to play the game at all — an excluded game contributes nothing, so no amount of turnover on it moves the requirement.
The contribution rate a low-edge game would need to be worth it
There is a clean way to test any game against slots without doing the whole calculation twice. The cost of clearing is (requirement ÷ contribution) × edge, so a game matches a 100%-contributing 4% slot when its contribution rate equals its own edge divided by 4%. The requirement itself cancels out, which means the answer is the same whether the multiplier is 10x or 35x.
| Game | House edge | Contribution needed to match a 4% slot |
|---|---|---|
| Video poker / blackjack | 0.50% | 12.5% |
| Live blackjack | 0.60% | 15.0% |
| Baccarat (banker) | 1.06% | 26.5% |
| European roulette | 2.70% | 67.5% |
| American roulette | 5.26% | 131.5% |
Blackjack needs 12.5% to break even against slots and is almost always offered 10%. European roulette needs 67.5%. American roulette needs 131.5%, a number no operator could offer, which is the mathematical version of saying it should never be used to clear a bonus. The 10% rate is not a partial discount on wagering. It is set below the level at which the low-edge games would be competitive, and it is set there deliberately.
What to read in the bonus terms before you deposit
Five lines in the terms decide whether an offer is worth taking, and the headline percentage is not one of them:
- The contribution table. Not just the slots figure — the excluded list matters more. Excluded is 0%, and 0% means the requirement can never be met on that game.
- Whether the requirement applies to the bonus or to deposit plus bonus. The same multiplier on “deposit + bonus” doubles the turnover on a 100% matched offer.
- The maximum stake per spin or hand while wagering. A £5 cap on a £10,000 requirement is two thousand hands, which is a time cost as well as a money one.
- The expiry window. Turnover you cannot physically complete inside the window is turnover you will not complete.
- The maximum withdrawal from bonus winnings. A cap here puts a ceiling on the upside while leaving the expected cost exactly where the table above puts it.
To run these numbers on a specific offer rather than the worked example, the wagering requirements calculator takes the bonus, the multiplier, the contribution rate and your game’s RTP and returns the stakes required and the expected cost. For the underlying mechanics — how requirements are worded, what counts as a qualifying bet and how bonus balances are separated from cash — start with understanding wagering requirements.
Frequently Asked Questions
What does game contribution mean in a casino bonus?
Game contribution is the percentage of each stake that counts towards the wagering requirement. At 100% a £1 stake reduces the requirement by £1; at 10% it reduces it by 10p, so you need ten times the turnover. Excluded games contribute nothing at all.
Why do table games only contribute 10%?
Because their house edge is far lower than a slot’s. A bonus is priced on the expectation that the requirement will cost the player something to clear; at 100% contribution a 0.5% edge game would cost about an eighth of what a 4% slot costs. The 10% weighting removes that advantage and then some — a game with a 0.5% edge would need 12.5% contribution merely to match a 4% slot.
Does the UK 10x wagering cap limit game contribution?
No. The cap limits the multiplier applied to the bonus. How much each game counts towards that requirement is still set in the operator’s own bonus terms, which is why a capped 10x offer can still mean £10,000 of blackjack stakes on a £100 bonus.
Is it cheaper to clear a bonus on slots or on blackjack?
On typical terms, slots. A £100 bonus at 10x costs about £40 in expected losses on a 96% RTP slot contributing 100%, against about £50 on blackjack contributing 10%, because blackjack needs £10,000 of stakes instead of £1,000. Blackjack produces a narrower spread of outcomes, but it is not the cheaper route.
How do I work out the real cost of a bonus offer?
Divide the wagering requirement by the contribution rate to get the stakes you actually need, then multiply that by the house edge of the game — 100% minus its RTP. If the result is larger than the bonus, the offer has a negative expected value on that game before you have played a hand.
Wagering requirements are designed to be turnover, not free money: the calculations on this page describe expected costs, not guaranteed outcomes, and no bonus is a reason to stake more than you planned to. 18+. If gambling stops being fun, see our responsible gambling resources.