How to play Criboku
Criboku is a daily logic puzzle built on cribbage scoring. You fill in the missing cards so that every row, column and corner square scores exactly the number shown beside it. Every puzzle has one solution, and you never have to guess — it can always be reasoned out.
The board
The grid holds sixteen cards. Twelve hands are scored on it, and each card belongs to three of them at once:
- the 4 rows and 4 columns;
- the 4 corner squares — each 2×2 block at a corner of the grid.
The shaded cells are one corner square. The other three sit at the remaining corners.
Above the grid sits the starter. It is shared by every hand: each hand is its own four cards plus the starter, five cards in all — exactly as in cribbage, where the cut card counts for everyone.
Fill in cards so the hands in each row, column and corner square match the score shown.
The pool
The pool lists all seventeen cards in the puzzle — the sixteen on the grid plus the starter — grouped by suit and sorted by rank. It tells you exactly which cards you have to work with.
Some pool slots are blank. Blank pool slots keep their place, so a gap between two cards tells you what rank(s) fit. If a suit reads 3♥ 8♥ ?♥ J♥, the hidden card is a heart ranked between 8 and the jack — a 9 or a 10.
Cards grey out in the pool as you place them, so what is left is what you still have to put somewhere.
Playing
You get one puzzle a day, and the week ramps up: Monday and Tuesday are easy, Wednesday and Thursday medium, Friday and Saturday hard, and Sunday is expert. The difficulty sits at the top of the page, and the row below it shows the puzzle's date with links either side to step between days.
- Tap a blank cell to choose a card to fill in, tap a filled cell to clear it.
- Row, column and corner-square scores fill in as you go, so you can see a hand's score the moment its four cards are down.
- If a score is shown for a hand you must match it. If not, you have to work it out yourself.
- The Total at the bottom adds up all twelve hands. For puzzles with some hidden hand scores, the total of known scores is shown next to the final total. On harder puzzles the final total is for you to determine.
- Stuck? The Hint button walks you through the next deduction, one step at a time. It explains the reasoning rather than just handing you a card.
Solving advice
Start by examining hands with high scores and low scores (especially 0 or 1). These usually have a very small range of cards that fit the constraint.
Look at card slots at the intersection of rows, columns, and/or corner squares whose hand score is provided. Often the subset of cards that fit one hand, and the subset of cards that fit an intersecting hand, only have one common member.
For hands whose score isn't provided, look at the difference between the total score of known hands vs. the final total (if shown). From that, work out what the unknown scores could be.
If all else fails, use the Hint button!
Scoring a hand (for cribbage newbies)
Every cribbage hand is four cards plus the starter. Add up everything below; a single card can count in several ways at once. The most a hand can score is 29.
Card values: ace is 1, number cards are face value, and jack, queen and king are all 10. (For runs, order still goes A 2 3 … 10 J Q K.)
| Scores | Worth |
|---|---|
| Fifteen — any set of cards adding to exactly 15 | 2 each |
| Pair — two cards of the same rank Three of a kind is three pairs (6); four of a kind is six pairs (12). |
2 each |
| Run — three or more cards in consecutive rank A run counts once for each way it can be made, so a duplicated rank doubles it. |
1 per card |
| Flush — all four cards in the hand are the same suit 5 if the starter is that suit too. |
4 |
| His nobs — a jack in the hand matching the starter's suit | 1 |
Note: no points are added to the total if the starter card is a jack. (In cribbage the dealer takes 2 for "his heels" when a jack is cut; Criboku leaves that out, since there is no dealer.)
A worked example
Hand 5♥ 6♠ 9♦ K♣ with starter A♥:
- 5 + 9 + A = 15 → 2
- 6 + 9 = 15 → 2
- 5 + K = 15 (the king counts 10) → 2
- No pair, no run, no flush, no nobs → 0
Total: 6
A trickier one
Hand 4♦ 5♠ 6♥ 9♣ with starter 6♦:
- 4 + 5 + 6♥ = 15, and 4 + 5 + 6♦ = 15 → 4
- 6♥ + 9 = 15, and 6♦ + 9 = 15 → 4
- Pair of sixes → 2
- Run 4-5-6♥, and 4-5-6♦ → 6
Total: 16