Latin Square
Number Place without the boxes: a gentle start.
Controls and saving
Tap a cell to select it. Use arrow keys to move, number keys to enter, M for notes and Delete to erase. Notes let you record your own candidates.
Progress is saved on this device when storage is available.
How to play
Tap an empty cell to select it, then press a digit below. A digit cannot repeat in a row or a column; in an N×N grid, each row and column holds 1 to N exactly once. Turn on Notes to write down candidates. Hints reveal a strategy, a cell, then the answer.
Learn more
Arrangements where each symbol appears once per row and column are called Latin squares, and Leonhard Euler is said to have studied them. These puzzles are generated for this site; tests check that every one has a single solution reachable by logical deductions alone. On a 4×4 grid there are 576 complete squares, a number the tests confirm by counting.