Poker is a card game in which players bet on the outcome of a hand. The game has many variations, but the rules are largely the same.

Once all players have 2 cards, a betting interval begins. The player to the left of the dealer makes the first bet, and each player in turn must put into the pot enough chips (representing money, for which poker is almost always played) to make his contribution at least equal to that of the player who made the last bet.

A player must be willing to fold his hand if it is not good enough to win the pot. In addition, the player must be willing to reveal his hand, and must not bluff or try to deceive his opponents.

It is important to understand how to read your opponent’s tells and learn their idiosyncrasies. It is also a good idea to study the rules of the particular poker variant you are playing.

It is important to understand how to calculate ranges. While new players will often try to put an opponent on a specific hand, more experienced players will work out the full selection of hands that the opponent could have and calculate how likely it is that they have one of those hands. This allows them to make more accurate decisions about whether to call or raise. They are also more likely to be able to take advantage of opponents who are slow to act.