Official Rulebook

KenKen is a numerical logic puzzle played on an NxN grid, where N is between 3 and 9. Each row and each column must contain every digit from 1 to N exactly once. Every sanctioned puzzle has a single, machine-verified solution.

Cages. Outlined groups of cells display a target and an operation. The digits inside must combine, using that operation, to reach the target. Single-cell cages state their digit directly. Digits may repeat within a cage only if they sit in different rows and columns.

Delta, Kappa and Sigma. Students compete in three divisions set by age. Each chapter publishes the age bands for its season, and a champion is crowned in every division.

Open. Adult solvers, when a championship includes an open field.

NO-OP. Advanced rounds may include NO-OP puzzles, where the operation is hidden and only the target is shown.

Rounds. International events run three timed qualifying rounds of 18, 22 and 25 minutes. Each round presents a fixed set of puzzles that all competitors solve at the same time.

Championship Round. The leading qualifiers advance to a 20-minute Championship Round, which decides the titles.

Time Limits. Competitors who exceed the limit are scored only on cells filled correctly.

Every puzzle is scored on three factors, in this order of priority.

• Completion: was the puzzle fully solved.
• Accuracy: were all cells correct.
• Speed: how quickly it was finished, used to break ties.

Champion of Champions. The highest overall score across all divisions earns the Champion of Champions title. Only sanctioned events count toward qualification for the International Grand Finale.

Materials. Pencil and paper only. No electronic devices, calculators, or reference materials. Notes within the grid are permitted.

Fair Play. Any form of assistance, communication, or pre-solved material is prohibited. Competitors agree to the Federation code of conduct on registration.

Verification. A puzzle counts as solved only when every cell is correct and all cage constraints are satisfied. Officials verify all solutions before final scoring.

Disputes. Solving disputes are resolved by the on-site judge, with final appeals heard by the Federation.

This rulebook is maintained by the KenKen Federation and amended only by a vote of ratified national chapters. For sanctioning, competitions, or press, reach us at info@kenken.com.