Rules of Cribbage

0) Set-up

Cribbage is best played with two players, but can easily be extended for three or four players. A standard 52-card deck of cards is required. Pen and paper will be useful for tracking the score. Traditionally a purpose-built pegging board is used to track the score.

1) Objective

Thoughout the game players score points, this is called pegging in Cribbage. The winner is the first player to peg at least 121 points. Score is pegged immediately when it is awarded (ties are not possible as score is only ever awarded to one player at a time).

2) Structure of the game

A game of cribbage consists of a non-fixed number of rounds. For the duration of a round, one player will be Crib and the other player will be Pone. Players alternate between being Crib and Pone between rounds. A round consists of the following phases: the deal, the play, and the show.

3) The deal

To begin, Crib and Pone are dealt six cards each. Players must select two cards to discard face-down to form The Crib, leaving them with a hand of four cards. After the discards, the remainder of the deck is cut and the top card is revealed. If the cut card is a jack (JC, JD, JH, or JS), then Crib immediately pegs 2 score. This rule is called his nibs.

4) The play

After the cut card is revealed, the players begin the play phase in which cards are "played" one-by-one from their hands of four cards. Note that the cut card does not alter the play phase. Pone is first to play. When a card is played, the count must be read aloud.

Aces count for 1.
Twos count for 2, threes count for 3, etc., tens count for 10.
Jacks, queens, and kings all count for 10.

For example, if Pone plays the four of diamonds (4D), they say "four"; then if Crib plays the nine of hearts (9H), they say "thirteen".

If the count reaches 31 (exactly), the last player to play a card pegs two score. Otherwise, if the count is less than 31, if the next player cannot play a card without the count exceeding 31, they must say "go". Once the remaining player cannot play any more cards (either because of the count, or because their hand is empty), they say "one for the go" and peg one score. It is important to note that a player must play a card if they can do so without the count exceeding 31. This means that a player may play twice in a row: if your opponent says "go", you may still have cards that can be played without the count exceeding 31. Once both players cannot play (and "one for the go" is called), then the count is reset to zero and play continues. If they have card(s) remaining, the next player to play a card is the one that did not play the last card.

During the play, the player that most recently played a card can score points when the following occur.

If the count reaches exactly 15, peg two score.
Pairs:
- If the two most recent cards have the same rank, peg two score.
- If the three most recent cards have the same rank, peg six score.
- If the four most recent cards have the same rank, peg twelve score.
Runs: if the ranks of the last x cards can be rearranged to form an (contiguous) sequence (of length x), peg x score. Importantly, x must be at least three. For example, if the last three cards are ten of spades (10S), the nine of diamonds (9D), and jack of spades (JS), then the player that played JS pegs three score as the ranks can be arranged into (9, 10, J). Runs do not wrap around; ace is low and king is high.

Pairs and runs cannot be carried over when the count is reset. For example, if the count reaches 31 when the eight of clubs (8C) is played, the count is reset to zero, and even if the eight of diamonds (8D) is the next card played, the "pair" is not pegged.

5) The show

Once the play has concluded, the players then calculate the value of their hands and The Crib during the show. First, the Pone's hand is scored, then the Crib's hand, and finally The Crib is scored.

Scores for the Pone and Cribs hands are calculated in the same way. The four cards in the hand are combined with the cut card; these five cards together score points with the following combinations.

Pairs:
- If the hand contains two cards of the same rank, peg two score.
- If the hand contains three cards of the same rank, peg six score.
- If the hand contains four cards of the same rank, peg twleve score.
Runs: for every collection of x cards whose ranks form a (contiguous) sequence (of length x), peg x score. For example, if the hand contains KC, JH, QC, and JD, then six score is pegged: (JH, QC, KC) and (JD, QC, KC) are both runs of three. However, one cannot break runs of longer runs score multiple shorter runs. For example, (3D, 4H, 5D, 6D) can only be pegged for four score; (3D, 4H, 5D) and (4H, 5D, 6D) cannot be extracted to peg more score.
Flushes:
- Four-card flushes: if all four cards from the hand (without the cut card) have the same suit, peg four score.
- Five-card flushes: if all four cards from the hand match the suit of the cut card, peg five score.
Fifteens: for every collections of cards whose counts sum to 15, peg two score. For example, the hand 5S, QD, 9D, JS, and QC will peg six score for 15s as (5S, QD), (5S, JS), and (5S, QC) all have counts summing to 15.
His nobs: if the hand contains the jack whose suit matches the suit of the cut card, peg one score. The rule is referred to as "one for his nob".

For example, suppose the cut card was KH and the hand was QD, JH, 4D, and JD, then this hand scores nine points.

Two score is pegged for pairs: (JH, JD).
Six score is pegged for runs: (JH, QD, KH) and (JD, QD, KH).
Zero score is pegged for flushes; the hand consists of dimonds and hearts.
Zero score is pegged for fifteens.
One score is pegged for his nobs.

Now, finally, The Crib is revealed: the four discarded cards are revealed and combined, again, with the cut card and scored. The scoring of The Crib is almost identical to the scoring of the Pone and Crib's hands. The one exception is that the four-card flush is not an available scoring combination. The score of The Crib is pegged by Crib.