How to Play Tentaizu

The Board

Every Tentaizu puzzle uses the same format: a 7×7 grid of 49 cells. Exactly 10 of those cells hide mines. The remaining 39 are safe. Some cells are pre-revealed with a number from 0 to 8. These numbers are your only clues — use them to deduce where every mine is hidden.

Unlike Minesweeper, the board does not change as you play. You never click to reveal a new cell. All clues are visible from the very first moment; your job is to interpret them.

Reading the Number Clues

Each number on the board tells you the exact count of mines in the eight cells surrounding it (horizontally, vertically, and diagonally). This is identical to the mine-count logic in Minesweeper.

The 2 above means exactly 2 of its 8 neighbors contain mines. At the corner of the board, a cell has only 3 neighbors; on an edge, only 5. The same counting rule applies — the number never exceeds the cell's actual neighbor count.

Controls

Every unknown cell cycles through three states when you interact with it:

• 💣 Mine flag — you believe this cell is a mine.
• ✓ Safe mark — you have logically confirmed this cell is safe.
• ? Unknown — not yet determined; the starting state of all cells.

Click (or tap on mobile) to advance the state forward. There is no penalty for incorrect flags — the puzzle only checks your answer when you've placed all 10 mine flags. Keep refining your deductions until all 10 mines are correctly identified and no safe cells are mistakenly flagged.

Win Condition

You win when exactly the 10 mine cells are flagged as mines and no safe cells are flagged. The moment this condition is met, the puzzle registers as solved and you can submit your time to the daily leaderboard.

The puzzle does not end on a wrong flag — you will not accidentally trigger a mine. This means you can test hypotheses: if a tentative flag leads to a contradiction, you know that cell must be safe.

Step-by-Step: Your First Solve

1. Scan for 0s and 8s first. A clue of 0 means every neighbor is safe — mark them all ✓. A clue of 8 means every neighbor is a mine — flag them all 💣. These are free deductions that cost no reasoning.
2. Look for satisfied constraints. If a clue cell already has exactly as many mine flags around it as its number, all remaining unknown neighbors must be safe. Mark them ✓ with confidence.
3. Look for forced mines. If a clue cell has exactly as many unknown neighbors as its remaining mine count (number minus flags already placed), every one of those unknowns must be a mine. Flag them all.
4. Track the global count. You have 10 mines total. Subtract your current flag count to know how many remain. As the number gets small (2, 1), the remaining unknowns are heavily constrained and often resolve quickly.
5. Compare overlapping clues. When two number cells share some neighbors, subtract one constraint from the other. If clue A = 2 and clue B = 1, and B's mine must lie among A's neighbors too, then A has exactly one mine in its exclusive neighbors. This subtraction technique is the key to cracking harder puzzles.
6. Repeat until all 10 mines are flagged. Every Tentaizu puzzle is designed to be fully solvable by these logical steps alone. If you feel stuck, look for a clue whose unknown neighbor count equals its remaining mine count — that clue will unlock the next deduction.

Daily Puzzle vs. Random Mode

The Daily puzzle is the same for every player worldwide. It resets at midnight UTC. Solve it to post your time to the global leaderboard and compare results with other players.

Random mode generates a fresh unique-solution puzzle on demand. Use it to practice techniques, warm up before the daily, or simply keep playing after you've already solved the day's puzzle.