Sudoku and Strimko are both grid-based logic puzzles you solve by pure deduction, so solvers naturally wonder how alike they really are. The short answer: Strimko is very close to Sudoku. Below we lay out what the two share, where they part ways, and whether the skills you have built on Sudoku will carry over.
- Grid: n×n Latin grid
- Closeness to Sudoku: Very Close
- Also called: Streams
What is Strimko?
A Latin-square grid where, on top of the rows and columns, curved "streams" of cells must each contain every number once. Here are the rules in full:
- Fill an n×n grid so each row and column holds the numbers 1-n exactly once.
- The grid is also threaded with streams - chains of n cells - and each stream must contain 1-n once too.
- A few starting numbers pin the puzzle down to one solution.
See a Strimko grid
Strimko is a Latin square with an extra twist: as well as the rows and columns, curved "streams" of cells must each contain 1 to n once. Below, a solved 4×4 grid - each row and column has 1-4, and the shaded stream (a winding chain of four cells) does too.
Rows and columns hold 1-4; the shaded stream (1, 2, 3, 4) does too.
The row-and-column Latin rule is Sudoku's own, and a stream behaves just like an extra region - so Strimko is about as close as a different puzzle gets. Treat each stream as a box and the same singles-and-elimination habits solve it outright.
What Strimko shares with Sudoku
- The row-and-column Latin rule is Sudoku's own, and streams act just like extra regions.
- It is solved by naked and hidden singles, exactly as Sudoku is.
- No arithmetic, no guessing - pure placement logic.
How Strimko differs from Sudoku
- Streams are winding chains, not 3×3 boxes, and the grid is usually smaller than 9×9.
- There is no box rule - the streams take that role.
Do Sudoku skills transfer?
Strimko is close enough to Sudoku that the same singles-and-elimination habits solve it outright - treat each stream as an extra region and you are already there.
Brush up on the technique that carries over: Naked Single.
The verdict
Strimko is Sudoku with its boxes swapped for winding streams - about as close as a different puzzle gets.
Prefer to stay with Sudoku?
If Strimko appeals, these Sudoku variants scratch the same itch and you can read up on each here:
Where to play it
If it was Sudoku you came for, the level is the choice that matters more than the variant - Strimko and Sudoku part ways on the rules, but a Sudoku grid can be a two-minute warm-up or an hour of work depending on nothing but how much of it you are given.
Difficulty and type are two separate dials here: the type sets the extra rule, the level sets how much of the grid you start with. Easy Sudoku leaves 36 of the 81 cells filled, so there is always an obvious next move somewhere; Evil Sudoku leaves 23, with no easy moves at all. Take it at the gentler end while the pattern is still new, and move up once it stops being a fight.