Kakuro techniques
Twelve techniques, in the order the solver tries them. Each guide has a worked board, a plain explanation and the exact steps to look for. The slugs match the hints in the app, so a hint can link straight to its guide.
01 · Basics
02 · Sum knowledge
Level 1
Unique Sum Partition (Magic Block)
Some sums have exactly one set of distinct digits. Fill the digits in, or cross out everything that is not part of the set.
Level 2
Minimum and Maximum Sum Bounds
The remaining sum of a run bounds what each of its cells can hold. Digits outside the bounds can be removed.
Level 2
Mandatory Digit
A digit that appears in every partition of a run must be somewhere in that run. If only one cell can take it, it goes there.
03 · Intersections
04 · Single digit in a run
05 · Subsets in a run
Level 3
Naked Pairs and Triples in a Run
Two cells limited to the same two digits consume those digits, so no other cell of the run can use them.
Level 3
Hidden Pairs and Triples in a Run
Two digits that can only go in the same two cells of a run are locked there, so those cells lose every other candidate.
06 · Combining runs
Level 4
Forced Combination (Partition Matching)
The digits of the run are known; match each one to a cell so that every cell is allowed to hold its digit.
Level 4
Locked Sum Residual
When a group of cells is locked to a fixed set of digits, its sum is fixed, and the rest of the run follows by subtraction.
07 · Last resort
Learn them in order
If you are new, read How to solve Kakuro first, then keep the sum cheat sheet open while you play.