The betting structure of a poker game is a more significant factor in its balance of luck and skill than the game variant being played. Higher forced bets and smaller limits increase the influence of chance. Smaller forced bets and larger limits increase the element of skill. Good games are carefully balanced so that skillful players will win in the long run while recreational players can win often enough for the game to be exciting to them.
Home games typically use a small ante only. Casino games typically use blinds for draw and community card games, and an ante plus bring-in for stud games (very small limit stud games may omit the ante). A good balance is for the total of all forced bets to equal one or two times the betting limit for a game. For example, if eight players play a game with a $2 betting limit, a $.25 or $.50 ante would make a well-balanced game, as would a game with $1 and $2 blinds, or a $.25 ante and $1 bring-in.
The sample deals in Poker/Game play show examples of each of these forced bets.
All such games have a minimum bet as well as the stated maximums, and also commonly a betting unit, which is the smallest denomination in which bets can be made. For example, it is common for a games with $20 and $40 betting limits to have a minimum betting unit of $5, so that all bets must be in multiples of $5, to simplify game play. It is also common for some games to have a bring-in that is less than the minimum for other bets. In this case, players may either call the bring-in, or raise to the full amount of a normal bet, called completing the bet.
Outside of the United States, pot limit and no limit games are the most common. Most American home games are played with a spread limit, while casino games are played with spread or fixed limits, though larger casinos may have a high-stakes pot limit or no limit game as well. Fixed limit and spread-limit games emphasise the skill of estimating odds, and are more influenced by chance. Pot limit and no limit games emphasis the skills of game threory and psychology, and are far less influenced by chance.
A universal rule in American casinos, and common in home games as well, is that any raise must at least equal the amount of the previous bet. For example, if a player in a spread limit or no limit game bets $5, the next player may raise by another $5 or more, but he may not raise by only $2, even if that would otherwise conform to the game's structure. The primary purpose of this rule is to avoid game delays caused by "nuisance" raises (small raises of large bets that don't affect the bet amount much but that take time). This rule is often overridden by table stakes rules (see below), so that a player may in fact raise a $5 bet by $2 if that $2 is his entire remaining stake.
In many casinos, there is a limit to the total number of raises allowed in a single betting round (typically 3 or 4, not including the opening bet of a round). For example in a casino with a 3-raise rule, if one player opens the betting for $5, the next raises by $5 making it $10, a third player raises another $5, and a fourth player raises $5 again making the current bet $20, the betting is said to be capped at that point, and no further raises beyond the $20 level will be allowed on that round. It is common to suspend this rule when there are only two players betting in the round (called being head up).
All casinos and many home games play by what are called table stakes rules, which state that each player starts each deal with a certain stake, and plays that deal with that stake. He may not remove money from the table or add money from his pocket during the play of a hand. This requires some special rules to handle the case when a player is faced with a bet that he cannot call with his available stake. A player also may not hide the amount of his stake from other players, and must disclose the amount when asked.
When a player is faced with a current bet amount that he has insufficient remaining stake to call, and he wishes to call (he may of course fold without the need of special rules), he bets the remainder of his stake and declares himself all in. He may now hold onto his cards for the remainder of the deal as if he had called every bet, but he may not win any more money from any player above the amount of his bet. For example, let's assume that the first player in a betting round opens for $20, and the next player to bet only has $5 remaining of his stake. He bets the $5, declaring himself all in, and holds onto his cards. The next player in turn still has the $20 bet facing him, and if he can cover it he must call $20 or fold. If he calls $20, thus ending the betting round, instead of collecting all bets into the central pot as usual, the following procedure is applied: since there is an all in player with only $5 bet, his $5, and $5 from each of the other players, is collected into the central pot, now called the main pot, as if the final bet had been only $5. This main pot (including any antes or bets from pervious rounds) is the most the all in player is eligible to win. The remaining money from the still-active bettors, in this case $15 apiece, is collected into a side pot that only the players who contributed to it are eligible to win. If there are further betting rounds, all bets are placed into the side pot while the all in player continues to hold onto he cards but does not participate in further betting. Upon the showdown, the players eligible for the side pot--and only those players--reveal their hands, and the winner among them takes the side pot, regardless of what the all in player holds (indeed, before he even shows). After the side pot is awarded, the all in player then shows his hand, and if it is superior to all others shown, he wins the main pot (otherwise he loses as usual).
There is a strategic advantage to being all in: you cannot be bluffed, because you are entitled to hold your cards and win the pot without risking any more money. The players who continue to bet after you are all in can still bluff each other out of the side pot, which is also to your advantage. But these advantages are more than offset by the disadvantage that you cannot win any more money than what your stake can cover. After all, the object of poker is not to win hands--it is to win money.
If a player goes all in with a raise rather than a call, another special rule comes into play. There are two rules in common use here: pot limit and no limit games always use what is called the full bet rule, while smaller fixed or spread limit games use either the full bet rule or the half bet rule. The full bet rule states that if the amount of an all in raise does not equal the full amount of the previous bet, it does not consitute a raise, and therefore does not reopen the betting action. The half bet rule states that if an all in raise is equal to or larger than half the bet being raised, it does constitute a raise and reopens the action. For example, a player opens the betting round for $20, and the next player has a total stake of $25. He may raise to $25, declaring himself all in, but this doesn't consitute a "real" raise, in the following sense: if a third player now calls the $25, and the first player's turn to act comes up, he must now call the additional $5, but he does not have the right to reraise further. The all in player's pseudo-raise was really just a call with some extra money, and the third player's call was just a call, so the initial opener's bet was simply called by both remaining players, closing the betting round (even though he must still equalize by putting in the additional $5). If the half bet rule is being used, and the all in player had raised to $30 instead of $25, then that raise would count as a genuine raise and the first player would be entitled to reraise if he chose to (this would create a side pot for the amount of his reraise and the third player's call, if any).
Because these rules are complicated (especially when more than one player goes all in, or there are pots to be split because of ties), informal home games often allow players to temporarily borrow money to add to their stake during a hand when necessary, which is called going light.
See also Poker/Game play.