🂡 Cribbage Guide

What Is Cribbage?

Cribbage is a two-player card game traditionally credited to the English poet Sir John Suckling in the early seventeenth century. It is usually scored on a long wooden board with pegs, which is where the verb "to peg" comes from, and it has stayed popular for centuries because every hand mixes three different skills: choosing what to keep, playing cards in sequence for small points, and spotting every scoring combination when the hands are counted.

Our version is two-player, six-card Cribbage against an AI opponent, played to 121 points, with every score counted for you automatically.

The Rules

A hand of Cribbage has four stages.

• The deal and the crib - each player receives 6 cards and places 2 of them face down in the crib, an extra hand that belongs to the dealer. You deal the first hand and the deal alternates after that. On this table you choose your discards by clicking two cards and pressing Send to crib.
• The cut - a starter card is turned from the deck. It counts as part of both hands and the crib. If it is a jack, the dealer pegs 2 points straight away, a bonus known as his heels.
• The play - starting with the non-dealer, the players take turns laying single cards face up and announcing a running count. Aces are 1, number cards their face value and jacks, queens and kings 10. The count may never exceed 31. Bringing the count to exactly 15 or 31 scores 2. Playing a card of the same rank as the one just played scores 2 for a pair, 6 for three of a kind and 12 for four. Completing a run of three or more consecutive ranks among the latest cards, in any order, scores 1 per card. A player who cannot play without going over 31 must say go; when neither player can continue, the last player to lay a card pegs 1 and the count starts again from zero.
• The show - the non-dealer's hand, the dealer's hand and then the crib are each counted with the starter. Every combination of cards that adds up to 15 scores 2. Each pair scores 2. A run of three or more consecutive ranks scores 1 per card, and every distinct run counts. Four cards of one suit in the hand score 4, or 5 if the starter matches; the crib scores a flush only when all five cards share a suit. Holding the jack of the starter's suit scores 1, called nobs.

The first player to reach 121 wins immediately, even mid-hand. The game refuses any card past 31 and lists each hand's score by category after the show.

Core Strategy

Keep the cards that count

Most of your points come from the show, so your first decision each hand is the most important. The most valuable card in the game is the 5, because sixteen of the fifty-two cards are worth ten and every one of them makes 15 with it. Suppose you are dealt 5♥ 5♣ J♦ Q♠ 7♣ 2♦. Keeping 5-5-J-Q gives four separate fifteens (each five with each face card) plus a pair: 10 points before the starter is turned, and any further ten-card or 5 on the cut adds more.

Discard with the crib in mind

When it is your deal, the crib is yours, so any points your discards create are points for you. Throw cards that work together: a 5, a pair, or two touching cards such as 7-8. When the AI deals, do the opposite. Take 4♦ 6♣ 7♥ 8♠ K♣ K♦ on the AI's deal. Keeping 6-7-8 with a king gives a fifteen (7+8) and a run of three for 5 points. Throwing the two kings would hand the AI a guaranteed pair in its crib, so throw one king and the 4 instead — two cards that are far apart in rank and do not add to 15.

Choose a safe lead

The safest opening card in the play is one below 5. Nothing makes 15 with a 4 or lower in a single card, so your opponent cannot score a fifteen in reply. Leading a 5 is the classic mistake, because any ten-value card answers it for 2. A ten-card lead is not much better against an opponent holding fives.

Think two cards ahead in the play

Try to leave the count where your next card can score. If you lead a 4 and the AI answers with a king, the count is 14 and an ace in your hand makes 15. Late in a sequence, holding a ten-card means any AI play that lands the count on 21 lets you finish at 31 for 2. Equally, avoid leaving the count at 5 (any ten-card makes 15) or at 21 when your opponent may hold a ten.

Hold a low card for the end

Near 31, small cards are gold. A player with an ace or deuce left can often play when the other cannot, collecting the point for the go or even reaching 31 exactly. Don't spend your lowest card early in a sequence unless it scores.

Play to the board

Near 121, position matters. When you are well ahead, peg conservatively. When you are far behind, keep high-ceiling hands and build a big crib on your deal. Remember the non-dealer counts first in the show, so on a close finish that hand can peg out before the dealer counts at all.

Common Mistakes to Avoid

• Giving away fives. A 5 in your opponent's crib is close to a gift of several points.
• Breaking up a strong hand for one pegging opportunity. A hand like 4-5-6-6 is worth 12 points in the show; no single card is worth that in the play.
• Leaving the count at 5 or 21. Both are one ten-value card away from 2 points for your opponent.
• Forgetting the starter. When choosing what to keep, think about which cuts improve your hand: a hand with a 5 and several ten-cards improves on a large share of the deck.

Playing Against Our AI

The AI sees only its own cards and discards, the starter and the cards already played; never your hand or your crib discards.

Difficulty	What to expect
Easy	Throws two random cards to the crib and plays a random card from those that fit under 31, with no attempt to score.
Medium	Keeps the four cards that score best on their own, counting its discards as a plus in its own crib and a minus in yours. In the play it takes the card that scores most right away, otherwise its lowest card.
Hard	Averages every split of its six cards over all possible starters, so it keeps hands that improve on the cut and rarely gives you fives or pairs. In the play it weighs each card's points against your likely reply, avoids leaving 5 or 21 or setting up pairs and runs, and saves low cards for the go.
AI Training	Scores its kept hand over every starter like Hard, but values the crib by also sampling the two cards its opponent might throw. In the play it simulates the rest of the pegging against hundreds of hands you could be holding and plays the card with the best average points difference. Over 960 test games it beat Hard 512-448; the cards still decide plenty.

Leading a 5 is costly against Medium and Hard. Medium is easy to bait with a low lead; against Hard, concentrate on sound discards and keeping a low card for the go.

Frequently Asked Questions

Why do kings and queens count as 10 but form runs in order?

The count and fifteens use card values, so every face card is worth 10. Runs use rank order instead, from ace (low) up through jack, queen and king, so 10-J-Q is a run and so is J-Q-K, but Q-K-A is not.

Do I have to count my own points?

No. Every score is added automatically, so there is no muggins rule and no risk of overlooking a fifteen.

What happens if I can't play without going over 31?

You can't lay that card. Your opponent continues playing as long as they can stay at or under 31, and when neither player can go on, the last player to lay a card pegs 1 for the go and the count resets to zero.

Does the dealer get an advantage?

Yes, the crib is an extra hand that only the dealer scores. Because the deal alternates every hand, the advantage evens out over a game, but it is why you should be generous with your discards on your own deal and stingy on the AI's.