What is All-In?

Going all-in means committing all of your remaining chips to the pot in a single action. In no-limit poker any player may go all-in at any point on their turn; once all-in, you can take no further betting action and simply await the remaining cards and the showdown. The key mechanic is the side pot. If you go all-in for less than another player wishes to wager, the surplus cannot be matched against you, so it is set aside in a separate pot that you are not eligible to win. You can only ever win, from each opponent, an amount equal to what you put in. Worked example: three players see a flop. Player A is all-in for £20. Players B and C each have £100 behind and want to keep betting. The first £20 from each of the three forms a £60 main pot, which A is eligible to win. Any further chips B and C wager — say £50 each — build an £100 side pot contested only between B and C. If A has the best hand at showdown, A wins the £60 main pot only; the £100 side pot goes to the better of B and C's hands. Why it matters: side-pot rules cap a short stack's reward and let deeper stacks continue to fight for additional chips. Understanding them prevents disputes over who can win what. Common mistake: a short-stacked all-in player believing a monster hand wins everything on the table. It does not — they are limited to the portion they could match. Going all-in also forfeits all post-flop control, so timing it well is a core tournament skill.