Sumo

About Sumo

Sumo is Mind Loft's take on greater-than sudoku, also known as inequality sudoku. The usual rules hold: every row, column and 3x3 box contains the digits 1 to 9 once. On top of that, each of the 108 edges inside the boxes is drawn as a small point aimed at the smaller of the two squares it separates, so the grid itself tells you which neighbour is bigger.

Because the signs carry so much information, the board prints very few digits. The week runs from easier to harder: Monday shows eight digits, then six, four and two, Friday shows none, Saturday shows two but needs harder logic, and the Sunday Edition gives nothing but the signs. Every board has a single solution that can be reached by logic alone.

A new board arrives at midnight Eastern time and is the same for everyone. Wrong entries are not flagged, so catching your own mistakes is part of the solve. A clean solve scores 10, and ties on the daily leaderboard are broken by time. Past boards are kept in Mind Loft's puzzle archive, and the game plays in the browser with no app or account.

Sumo suits players who know classic sudoku and want a variant that leans on comparison rather than given digits. Mind Loft publishes it beside its other daily sudoku variants, such as Suds (classic), Mercury (thermo), Polka (kropki) and Diag (diagonal).

How to play Sumo

1. Open mindloftdaily.com/sumo and press Start to load the day's board.
2. Read the signs: each bent line inside a box points at the smaller of its two squares.
3. Tap a square and then a number, or pick a number and then tap squares, to fill the grid.
4. Place 1 to 9 once in every row, column and 3x3 box while obeying every sign.
5. Use Notes for candidates and Hint if you are stuck, then finish the grid to submit your score and time.

Screenshots

Tips

• A 1 can only sit where every sign around it points into that square, and a 9 only where every sign points away.
• Follow chains of squares that keep getting smaller inside a box: a chain of four steps down means its top square is at least 5.
• Mistakes are not marked, so check each row and box before you fill the last few squares.

Questions