This special Sudoku puzzle appeared in the 2025 International Logic Olympiad this summer! Read more here about the competition and try your hand at some of the problems contestants faced.
The objective of Sudoku is to fill each row, column and sub-grid with exactly one of each number from 1-9. A conflict arises if you repeat any entry in the same row, column or sub-grid. For more, select "How to Play" in the game's dropdown menu. Use the "Play Together" option in the navigation bar to invite a friend to play this puzzle with you and enter numbers at the same time.
We’d love to hear from you! E-mail us at games@sciam.com to share your experience.