Pot-Limit
In pot-limit poker, when a player chooses to bet or raise, the size of the raise can be anywhere from the minimum bet to the size of the pot. The minimum bet will be equal to the size of the large blind. The minimum raise is the size of the last bet or raise. A player who wishes to bet or raise but does not have enough chips to make the minimum wager may go all-in with their remaining chips.
Unlike limit and no-limit, a player is entitled to the current count of the pot.
Stud variations without blinds are sometimes played in a pot-limit format, with the minimum bet being the size of the bring-in.
The maximum bet in a round without action is simply the size of the pot.
The maximum raise is the size of the pot after the call of the initial action.
Examples
For an example, suppose you are playing in a pot-limit Omaha tournament at the 100/200 level. Like no-limit, this means that the small blind is 100 and the large blind is 200. In this example, the action folds to the player on the button, who says raise.
The minimum raise in this situation would be 200, making it 400 to-go.
The maximum raise is the size of the pot. In this case, that is 700 to-go, or a raise of 500 on top of the 200 blind. That is, the button says "raise", allowing them to call 200; there is now that 200 + 100 small blind + 100 big blind in the pot; the button can make it 700 to-go.
In this example, suppose the big blind calls. There is 1500 in the pot (100 small blind + 700 big blind + 700 button). On the flop, the big blind bets out the maximum, 1500. The button says "raise pot". It is now 6000 to-go (1500 pot+1500 bet+1500 call = 4500 raise).
A common shortcut is that a pot raise of a pot bet is 4✕ the pot bet, which can be seen in the example above.
More generally, a pot raise of any bet is 3✕ the bet, plus any other money behind. This requires a little bit more explanation.
For example, suppose we have a new hand at the 100/200 level. The button limps, the small blind completes and the big blind checks. The pot is 600.
On the flop, the small blind bets out 200. The big blind calls. The button says "raise pot". He laboriously puts out 200, then counts 400 (pot), plus the three 200 bets this round, and makes it 1200 to-go.
One of the players at the table will usually "helpfully" pipe up at this point and point out that the shortcut is to take 3✕ the bet, plus any money behind. In this case, that's 3✕200 + 200 (caller) + 400 (pot) and that's still 12 to-go.
For a stud example, suppose you are playing a pot-limit London Lowball tournament where the ante is 100 and the bring-in is 150. With eight players, the pot starts at 8 ✕ 100 = 800. Player A brings it in for 150. Player B says raise. The minimum raise Player B can make is 150 (the size of the bring-in), to 300 to-go; and the maximum raise is 800+150+150 = 1100, to 1250 to-go (call 150 + raise of 1100).
Suppose Player B raises 500, to 650 to-go.
Player C then says "pot". A pot-sized raise will be 3✕650, + 950 = 2900 to-go, or a raise of 2250.
Unlike limit poker, the half bet size rule does not apply to pot-limit poker. A player who has already acted and is not facing a full-size wager may not subsequently raise an all-in bet that is less than the minimum bet or less than the full size of the last bet or raise.
There are an unlimited number of raises available to the players. Check and raise is allowed.