Sudoku and Ripple Effect are both grid-based logic puzzles you solve by pure deduction, so solvers naturally wonder how alike they really are. The short answer: Ripple Effect is moderate 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: Rooms grid
- Closeness to Sudoku: Moderate
- Also called: Hakyuu
What is Ripple Effect?
A grid split into rooms; each room of size m holds 1–m, and equal digits in a line must be spaced at least that many cells apart. Here are the rules in full:
- Each room of m cells is filled with the numbers 1–m, one each.
- If a digit repeats in a row or column, the gap between the two must be at least that digit's value — two 3s need three cells between them.
- Given numbers narrow it to a single solution.
See a Ripple Effect grid
Ripple Effect divides the grid into rooms; a room of m cells holds 1 to m. On top of that, if a digit repeats in a row or column, the gap between the two copies must be at least that digit's value. Below, a three-cell room reads 1, 2, 3.
A Ripple Effect board: each coloured room of m cells holds 1…m (the purple room reads 1-2-3), and where a digit repeats in a line the gap between the copies must be at least that digit's value.
Rooms filled with a fixed run of numbers echo Sudoku's regions and its no-repeat idea, and it is solved by naked singles and elimination — no guessing. The distance rule, where a digit's value sets how far apart repeats must sit, is the one part with no Sudoku parallel.
What Ripple Effect shares with Sudoku
- Rooms filled with a fixed run of numbers echo Sudoku's regions and no-repeat idea.
- It is solved by naked singles and elimination, never guessing.
How Ripple Effect differs from Sudoku
- The spacing rule — distance depends on the digit — has no Sudoku parallel.
- Rooms vary in size, so the number range shifts room to room, and there are no boxes.
Do Sudoku skills transfer?
The room-filling and single-candidate elimination feel familiar; add the distance rule as one more way to rule a digit out, and a Sudoku solver adapts fast.
Brush up on the technique that carries over: Naked Single.
The verdict
Ripple Effect keeps Sudoku's region-filling logic and layers on a distance rule all its own.