Score
0
Time
150s
Best
—
Logic puzzle, also known as Tectonic. The grid is split into outlined regions; a region of n cells must hold the numbers 1 to n, once each. No two identical numbers may touch, not even diagonally. Solve as many as you can in 150 seconds.
The board is divided into outlined regions of different sizes. A region with one cell holds a 1; a region with three cells holds 1, 2 and 3; a region of five cells holds 1 through 5 — each number once. Some cells start filled in.
The second rule ties the regions together: no two cells with the same number may touch, in any of the eight directions, including diagonally. So a 2 can never sit next to, above, below, or kitty-corner from another 2.
Tap an empty cell to select it, then tap a number on the pad to place it (you can only enter numbers up to that region's size). Tap ✕ to clear the selected cell. Given numbers are fixed. Any number that breaks a rule turns red so you can spot clashes immediately.
Finish a grid and the next appears at once. Solve as many as you can before time runs out.
Start with the smallest regions. A single-cell region is just a 1, placed for free, and a two-cell region is a 1 and a 2 in some order — and the no-touching rule usually fixes which way round. These tiny regions seed the rest of the board.
Use a placed number to forbid its value all around itself. Once a 3 is down, no other 3 can sit in any of its eight neighbours — so scan those neighbouring regions and cross 3 off their options. Often that leaves a region with only one cell that can take a particular number.
Look for a value that fits only one cell in a region. Within a region of size n, each number 1..n must appear once; if the no-touching rule blocks a number from all but one of the region's cells, it is forced there. This is the workhorse deduction, mirroring 'hidden singles' in Sudoku.
The biggest numbers are often the easiest. In a five-cell region the 5 has to avoid every neighbouring 5, and high numbers appear rarely, so they tend to have just one legal home. Place the extremes first, then let the no-touch ripples force the middle values. In the timed mode, chase these forced cells rather than guessing.