The rules will be explained referring to the American variant Texas Hold’em, which is the most popular variant of poker in casinos and poker card rooms across North America and Europe. The players are given two cards each called “pocket cards” or personal cards. These are only visible to the player who receives them.

Based on a probabilistic calculation (but not only) each player decides at his turn which action to do carry out in order to win the round (hand) or whether to save money if this objective was not possible. Each player, in a clockwise direction, can therefore decide to: a) bet: putting money in the centre of the table (which will add to that of the opponents and will form the cash-prize to play for) to force the opponents to “pay” the same sum to continue playing. b) fold: pushing one’s own cards to the centre of the table renouncing on playing but also avoiding to have to put further money on the plate. c) call: “pay” a sum equal to that bet by the players who preceded so as to continue the game. d) rise: this consists in looking at the bet of the preceding players and adding more money so as it is them who must to decide whether to pay or not to continue playing. e) check: when no one before has bet or rose, this player can remain in the game without paying.

The game continues with the distribution of 5 community cards which will be placed in the centre of the table and that all players can use to form their hand (combination of 5 cards). The community cards are distributed in three phases: flop, where 3 community cards are given; turn, which adds one community card; river which adds the last community card. Before the flop and after each phase of distribution of the community cards the players have the possibility to carry out one of the five actions listed above.

The game finishes when only one player is left after all the other players passed, or, when a winner is announced based on the combination of highest value. This second possibility is called showdown and foresees that all players still in competition after the last sequence of actions (following the river) show their 2 personal cards so as it is possible to see who has the highest hand.