What is Suguru?
Suguru is a region-based logic puzzle, also known as Tectonic. The grid is split into bold outlined blocks, and each block must contain the numbers from 1 up to the number of cells in that block.
This free Suguru online game lets you play 5x5, 6x6, 7x7, 8x8, 10x10 and 12x12 puzzles on easy, medium and hard difficulty. Every generated puzzle is checked by the in-browser solver so it has a single solution before it is shown.
- A two-cell region contains 1 and 2.
- A five-cell region contains 1, 2, 3, 4 and 5.
- Larger cages can contain 1 to 6 or 1 to 7.
- The same number cannot touch horizontally, vertically or diagonally.
- Regions can have different shapes and sizes.
- Use logic from region limits and neighbouring cells to place each number.
How to play Suguru online
Click or tap an empty square to select it, then use the number buttons to enter a value allowed in that region. A three-cell region only accepts 1, 2 and 3; larger cages can accept up to 6 or 7.
Use Check for feedback without revealing the whole answer. Hint fills one correct cell, Undo steps back, Solution reveals the completed grid, and New puzzle builds another unique Suguru for the selected size and difficulty.
- Start with one-cell and two-cell regions because their choices are narrow.
- Look around each clue and remove any matching value from all touching cells.
- Count missing numbers inside each region.
- Use diagonal contact as carefully as side contact.
- Switch to a larger grid when the rules feel natural.
Suguru rules
Suguru rules are compact, but they create rich deductions. Each outlined region is a small set of numbers, and the region size tells you the highest number that can appear there.
The adjacency rule is the key difference from many other number puzzles. Two equal numbers cannot touch by an edge or a corner, even when they belong to different regions.
- Each region contains each number from 1 to the region size exactly once.
- A cell can never contain a number larger than its region size.
- Equal numbers may not touch horizontally.
- Equal numbers may not touch vertically.
- Equal numbers may not touch diagonally.
- A proper Suguru puzzle has one solution.
Suguru strategy tips
Good Suguru strategy begins by treating every region as a mini set. If a region has four cells, its missing values are only 1, 2, 3 and 4, so every clue nearby removes options quickly.
Harder puzzles often turn on contact pressure. A placed 3 can block up to eight neighbouring cells from also being 3, and that can force a hidden single inside a nearby region.
- Mark the missing numbers for each region in your head.
- Use given clues to eliminate the same value from all touching cells.
- Check diagonal neighbours before placing a number.
- Find cells that are the only possible place for a value in a region.
- When stuck, compare two neighbouring regions that need the same number.
Suguru grid sizes and difficulty
Small Suguru puzzles are ideal for learning because every region is close to every clue. Larger grids add more regions, more diagonal contacts and longer chains of deduction.
Easy puzzles keep more starting numbers. Medium puzzles remove more clues while staying approachable. Hard Suguru puzzles have fewer givens and rely more on indirect region logic, but the generator still checks for a unique solution.
- 5x5 Suguru is a quick starter grid.
- 6x6 and 7x7 Suguru add more room for mixed-size cages.
- 8x8 and 10x10 Suguru give a bigger daily-style challenge.
- 12x12 Suguru adds wide-board space, 6-cell cages and 7-cell cages.
- Easy, medium and hard change clue density and solving pressure.
- Every puzzle is solved-count checked before play.
A worked Suguru deduction
Suguru almost always opens at its smallest regions. A one-cell region can only hold 1, so fill it instantly — and because equal numbers may not touch even diagonally, that single 1 forbids a 1 in all eight surrounding cells at once. A two-cell region holds just 1 and 2, so a nearby clue often fixes which cell is which.
From there the no-touch rule does the heavy lifting. Place a number, then sweep its eight neighbours and cross that value off each of them. Often a neighbouring region is left with only one legal square for that value — a hidden single — and placing it triggers the next sweep. Chaining these single-value eliminations is how most Suguru grids unravel without guessing.
- A one-cell region is always 1.
- A placed number bans that value from all eight touching cells.
- A two-cell region is just 1 and 2, decided by its neighbours.
- After each placement, sweep the eight neighbours for eliminations.
- Look for a value with only one legal cell left in a region.
Place the biggest number first
A useful habit is to chase the largest number in each region. In a five-cell region the 5 appears exactly once, and like every value it cannot touch another 5 in any direction. High numbers are rarer across the board than 1s and 2s, so they have far fewer legal homes, which makes them the easiest to pin down.
Work from the big regions inward. The top value of a large cage, hemmed in by the same value in nearby cages and by its own region's other numbers, frequently has just one possible cell. Lock those in, and the smaller numbers fall into place around them. By contrast, 1 is the most common value, so use it as a sieve rather than a target: every 1 you place clears 1s out of a whole neighbourhood.
- The biggest value in a region appears once and is the rarest.
- Rare high numbers have the fewest legal cells, so place them early.
- Start from the large regions and work inward.
- Use 1s as a sieve: each one clears its eight neighbours.
- Let the fixed high numbers force the smaller ones around them.
Suguru, Tectonic and Naoki Inaba
Suguru was created by Naoki Inaba, one of Japan's most prolific puzzle designers. It spread widely in Europe — especially the Netherlands, where it is known as Tectonic — and elsewhere it appears as Number Blocks. Whatever the name, the rules are the same: fill each region with 1 up to its size, and never let equal numbers touch.
Unlike Sudoku, Suguru has no fixed grid of rows, columns and boxes; its regions vary in shape and size, and the touch-in-any-direction rule replaces Sudoku's line constraints. The version here keeps that exact rule set and offers boards from 5x5 up to 12x12, so you can start small and grow into 6-cell and 7-cell cages.