Chiidoku combines Sudoku and Minesweeper elements: Sudoku-style row and column checks plus a colour-region checklist before every placement.
This page gives the plain-language rules and a first-puzzle checklist. The official Roblox listing — rechecked October 25, 2026 under the game's new Catdoku name — says each row, column, and colour area has one Cat (the tokens were Chiikawa characters before the October 2026 rename) and that two Cats cannot touch, including diagonally. Every puzzle has one solution and can be solved through logic without guessing.
For Chiidoku how to play, start with the two puzzle traditions the official listing names, Sudoku and Minesweeper, and how they inform the stated constraints: rows, columns, colour regions, and the no-touching rule each get their own check before you place a character. The listing also states that every puzzle has one solution and can be solved through logic without guessing. If a guide or video disagrees, use the current official Roblox listing and the board in front of you instead of trusting reposted copy.