Ripple Effect

In Ripple Effect, also known as Hakyuu, the grid is divided into irregularly shaped rooms by bold lines. Solvers must fill each cell with a number so that a room of size N contains the integers 1 through N exactly once. Additionally, identical numbers placed in the same row or column must be separated by a specific number of cells.

If two identical numbers are placed in the same row or column, they must be separated by at least that number in cells. For example, two 2s in the same row must have at least two cells between them. This creates a 'ripple' effect when placing digits across different rooms.

Ripple Effect is also known as Hakyuu. It is a number-placement puzzle published by the Japanese company Nikoli. The puzzle relies heavily on its unique spacing rule to challenge the solver.

Ripple Effect is published by Nikoli, the famous Japanese puzzle company known for popularizing Sudoku. Nikoli introduced the puzzle to a global audience through its various puzzle magazines. Their version relies on pure logic and does not require mathematical arithmetic.