All in means putting every chip you have in front of you into the current hand. It comes from poker, where table stakes rules let you bet everything you have on the table but nothing more. In casino slang it also describes staking a whole balance on one bet, which changes how quickly money goes but never the house edge.
In poker, going all in means betting all your chips on the current hand.
An all-in player can win only the main pot; extra bets between other players form a side pot.
Staking your whole balance on one roulette bet still carries the same 2.70% edge on a single-zero wheel.
UK online slot stakes are capped at £5 a spin (£2 for 18 to 24s), so an all-in spin above that is not possible.
Origin
Poker table stakes
Means
Betting all your chips in one hand
Side pot
Formed when others bet beyond an all-in
£100 all in on red
Wins 18 in 37 (48.65%)
UK slot stake cap
£5 (25+), £2 (18–24)
All in: the poker definition
In poker, a player goes all in when they bet every chip they have in the current hand. The rule behind it is table stakes: you may only bet what was on the table at the start of the hand, so you cannot reach into your pocket mid-hand, and no one can force you out simply by betting more than you have. If an opponent bets £200 and you have £80 left, you can call all in for £80.
This entry in the casino glossary covers that rule, the side pots it creates, and what "all in" means when people use it about casino games such as roulette, where there is no opponent to match.
How all-in side pots work
Once a player is all in, they can win only the amount they have matched from each opponent. Any further betting between the remaining players goes into a separate side pot that the all-in player has no claim on. Here is a three-player example.
All-in side pot example
Player
Chips put in
Eligible for
A (all in)
£20
Main pot only
B
£50
Main pot and side pot
C
£50
Main pot and side pot
Main pot
£20 × 3 = £60
A, B and C
Side pot
£30 × 2 = £60
B and C
Find the smallest all-in amount (A's £20).
Take that amount from every player still in the hand to build the main pot (£60).
Put everything each player bet above it into a side pot (£30 each from B and C).
Award the side pot first between the players eligible for it, then the main pot among everyone.
If A has the best hand, A wins £60 and the better of B and C takes the £60 side pot. If B has the best hand, B wins both pots.
All in at casino games against the house
Banked games such as blackjack and Casino Hold'em have no all-in rule because you play against the dealer, not other players. Your extra bets are fixed by the game, for example a Call of twice the ante, and the table's betting limit sets how much you can stake.
In everyday casino talk, though, "going all in" means staking a whole balance on a single bet. The maths is plain. £100 on red at single-zero roulette wins 18 times in 37 (48.65%) and loses 19 times in 37 (51.35%). The expected value is £100 × (18 − 19) / 37, a loss of about £2.70, which is the same 2.70% house edge you face on any bet at that wheel.
What changes is speed and variance, not cost per pound. One all-in bet ends the session in seconds, either doubled or empty. Smaller bets spread the same edge across more spins. Neither approach turns a game with a house edge into one you are expected to win.
All in, betting systems and gambler's ruin
Doubling systems tend to end in an all-in bet. The Martingale doubles after every loss, so a run of losses quickly pushes the next stake past what you have left or past the table maximum. Wizard of Odds' review of betting systems (opens in a new tab) describes a craps simulation in which a Martingale bettor went broke in 19.65% of sessions, while the overall loss rate matched flat betting.
The wider principle is gambler's ruin: a player in a game with negative expected value will eventually lose a finite bankroll whatever staking pattern they use, as the Wikipedia article on gambler's ruin (opens in a new tab) sets out. Going all in only makes the end arrive sooner.
Feeling the urge to go all in to win back losses is a warning sign. Our page on chasing losses explains why, and the National Gambling Helpline on 0808 8020 133, run by GamCare (opens in a new tab), is free and open 24 hours a day.
UK rules that cap an all-in bet
Online slots: a maximum of £5 per game cycle for players aged 25 and over and £2 for those aged 18 to 24, under the online slot stake limits.
Table and live games: no legal stake cap, but every table sets its own minimum and maximum.
Bonus play: many offers set a maximum bet while a bonus is active; Casumo's is £5.
Credit cards cannot be used to gamble in Great Britain, so you cannot fund an all-in bet on credit through a card.
None of these offers rewards large single bets, and two of them limit stake size while the bonus is live. 18+ and terms apply.
Casumo: opt in and deposit at least £20 for a 50% bonus up to £100, wagered 10x within 7 days, with a £5 maximum bet while the bonus is active. 10bet: a 100% match up to £25 on a first deposit made within 7 days of choosing the casino offer, wagered 10x on slots within 3 days, maximum bonus winnings £1,000, Skrill and Neteller excluded. Coral: deposit and bet £10 on slots for 100 free spins at 10p each on selected games, valid for 7 days with no wagering on winnings; Neteller, PayPal, Paysafe, Skrill, prepaid cards and certain debit cards do not qualify.
Significant terms: 18+. New customers only. Opt-in required. 50% deposit bonus up to £100 on first deposit. Minimum deposit £20. 10x wagering on the bonus amount. Maximum bet or spin £5. Bonus valid for 7 days. Game, play and payment method restrictions apply. Full T&Cs apply. GamCare.org.uk
Significant terms: 18+. New UK customers only. Select the casino welcome bonus at sign-up and make your first deposit within 7 days. 100% bonus up to £25. Wager the bonus 10x on slots within 3 days. Maximum bonus winnings £1,000. Skrill and Neteller deposits do not qualify. Bonus is not redeemable. Full T&Cs apply. GamCare.org.uk
Read our 10bet reviewLicence: Blue Star Planet Limited, Gambling Commission account 43173. Offer checked 5 October 2026.
Significant terms: 18+. New players only. Offer runs 01/10/2026 to 01/02/2027. Deposit (certain types excluded) and bet £10+ on slot games to get 100 free spins (selected games, £0.10 each, 48 hrs to accept, valid 7 days). No wagering on free spin winnings. Deposits by Neteller, PayPal, Paysafe, Skrill, prepaid cards and certain debit cards do not qualify. Restrictions and T&Cs apply. GamCare.org.uk
Read our Coral reviewLicence: LC International Limited, Gambling Commission account 54743. Offer checked 5 October 2026.
18+. Every casino game has a built-in house edge, so over time you should expect to lose what you stake. Set a budget before you play and stop when it’s gone: safer gambling tools and support. Free, confidential help: National Gambling Helpline 0808 8020 133.
Frequently asked questions
What does all in mean in poker?
It means betting all the chips you have on the table in the current hand. Under table stakes you cannot add money during a hand, and you can always call a bigger bet for whatever you have left. Once all in, you take no further part in the betting and can win only the main pot. Our casino poker vs poker page explains how this differs from games against the dealer.
What happens if someone goes all in and I have more chips?
You only need to match their all-in amount to stay in the main pot. If you and other players bet more, the extra goes into a side pot that the all-in player cannot win. At showdown the side pot is settled first among those who contributed to it, then the main pot. The table in this entry shows a worked example, and our hand entry covers showdown basics.
Can you go all in at a casino table game?
Not in the poker sense. In banked games like blackjack or roulette you play against the house, so there is no opponent to match and no side pot. You can stake a large share of your balance, but only up to the table maximum. The edge per pound stays the same however much you bet. Our table limit entry explains how maximums work.
Is going all in on red a good idea?
It does not improve your expected result. A single £100 bet on red at a single-zero wheel wins 48.65% of the time and costs £2.70 on average, the same 2.70% edge as smaller bets. It simply ends the session in one spin. Treat gambling as paid entertainment and stake only what you planned to spend. See red or black roulette for the full odds.
Can I go all in on an online slot in the UK?
Only up to the legal stake limit. Online slot stakes are capped at £5 per game cycle if you are 25 or over and £2 if you are 18 to 24, and the cap covers further stakes made within the same game cycle. Those limits apply to slots, not to table or live games. Read our online slot stake limits page for the dates and details.
Why do betting systems often end in an all-in bet?
Because systems like the Martingale double the stake after each loss, and stakes grow fast. Starting at £5, seven losses in a row take the next bet to £640, so many players hit their bankroll or the table maximum and end up staking what is left. The system does not change the house edge on any bet. Our roulette betting systems page walks through the maths.
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