Suirodoku has 6 difficulty levels — Easy, Medium, Hard, Expert, Master and Diabolic. The only thing that changes between them is the number of starting clues: the fewer clues you get, the more of the grid you must deduce yourself. This guide explains what each level asks of you, and how to climb from one to the next.
Deep dives: Easy (88) · Medium (75) · Hard (62) · Expert (52) · Master (43) · Diabolic (36)
How difficulty works
Every puzzle starts with a fixed number of clues (a digit, a color, or both, already placed): Easy 88 · Medium 75 · Hard 62 · Expert 52 · Master 43 · Diabolic 36. All grids are generated server-side with a mathematically proven unique solution — no guessing is ever required, at any level. The rules never change: each row, column and 3×3 region contains the digits 1-9 AND all 9 colors, and each of the 81 digit-color pairs appears exactly once.
Easy (88 clues) — build the reflexes
Most of the grid is already filled: your job is to learn to read colors as information. Scan a row for the one missing digit, a region for the one missing color. Tap a cell repeatedly to cycle the highlight modes (same color, same digit, row/column, region) — knowing these views cold is what makes every later level possible.
Medium (75 clues) — the everyday grid
Single-step deductions still carry you through most of the grid, but you will start crossing two facts: « this cell’s digit is known, and only one color is still free here ». The Daily Challenge — one worldwide grid per day — lives near this level, so Medium is the perfect training ground for it.
Hard (62 clues) — think in pairs
This is where the Rainbow Technique (track one digit across all 9 colors to find the missing one) and the Chromatic Circle (track one color across all 9 digits) become your main tools. Half-clues — a digit without its color, a color without its digit — start doing real work.
Expert (52 clues) — notes become mandatory
Below ~55 clues, holding candidates in your head stops working. Use the notes system to mark possible digits and possible colors per cell, and let eliminations cascade: completing a digit-color pair somewhere removes candidates everywhere.
Master (43 clues) — deep scanning
Long deduction chains appear: you will place cells whose justification spans three or four other regions. Work systematically — one digit through all colors, one color through all digits — and trust that a unique path always exists.
Diabolic (36 clues) — the summit
Barely a third of the information is given. Every technique above is required, plus patience: the 81-pair constraint becomes your strongest ally, because each pair placed anywhere is information everywhere. Finishing a Diabolic grid without hints is the game’s true black belt.
Which level should you play?
Play the level where you finish most games without hints, but not all. Each level has its own separate Ranked rating, so climbing never risks the rating you built elsewhere. And whatever your level, the free Suirodoku web game and the mobile apps share the same grids, rules and progression.