Poker is a card game in which players wager money on the outcome of hands that they receive from a random distribution. The player with the best 5-card hand wins all the money in the pot. The game contains some strategic elements, but it is primarily a game of chance.

Before the cards are dealt, each player must place an initial amount of money into the pot. This is known as a buy-in. Players can then choose to discard their cards and take new ones after a betting phase has finished. If more than one player has a winning hand, they share the money in the pot. Alternatively, players may choose to reveal their hands and collect the entire pot.

It has been suggested that the game of poker provides a unique window into human nature because it offers a glimpse at how humans deal with uncertainty. Indeed, the foundational 1944 book on mathematical game theory by mathematician John von Neumann and economist Oskar Morgenstern used poker as an example of a game that could be reduced to a finite number of pieces and rules that ruled their use.

The game of poker is also unique in its appeal to amateurs. For this reason, there is a lot of enthusiasm in the pro community for measures that tilt the game slightly in favor of amateurs. The pros see it as an opportunity to test their mettle against a broader range of talent.