How to play

  • Each puzzle consists of a 6x6 grid of numbers, where one number is already selected (black circle);
  • Using only logic (no guessing needed), choose the numbers so the sum in every row or column is 9 or less:
    • Click once on a number to remove it from the grid;
    • Click twice to select it (blue circle);
    • Click three times to remove the marks.
  • Each number (1 to 9) must appear exactly once;
  • A red mark will alert you if the sum in a row or column is more than 9;
  • The game ends when there are precisely 9 unique numbers selected on the grid and the sum rule is followed.


  • If this is your first time playing, try to solve the "very easy" puzzle before playing the other ones;
  • You can start by eliminating duplicates of the given number(s);
  • If a number appears only once, then it must be in the solution (see Naked Singles in our Sudoku Guide);
  • For more strategies that can be applied in this game, look at Naked Pairs and Pointing Pair in our Sudoku Guide. These kind of strategies can be applied to any logic game, so it's worth understanding them.

More games

Greek Logic
Greek Logic

Fill the grid using the Greek letters.

Logic Equations
Logic Equations

Using logic and basic algebras, solve the equations.

Logic Grid Puzzles
Logic Grid Puzzles

Complete the grid by using logic and the given clues of each problem.

Zebra Puzzles
Zebra Puzzles

Use logic deductions to solve problems that are similar to the Einstein's Riddle.