天体図 – 無料デイリー論理パズル

What is Tentaizu?

Tentaizu (天体図) is a pure-logic deduction puzzle from Japan. The name translates to star chart or celestial atlas — evoking the image of mines scattered across a grid like stars across the night sky. The puzzle is played on a compact 7×7 grid with exactly 10 hidden mines. A set of numbered clues are pre-placed on certain cells; each number tells you precisely how many of its eight neighboring cells contain a mine, exactly as in Minesweeper. Your task: use logic alone to identify all ten mines.

What makes Tentaizu exceptional is its guarantee of solvability. Every puzzle is carefully constructed so the given clues are sufficient to deduce every mine's location through pure reasoning — no random clicking, no guessing, no luck. If you reach a dead end, you haven't made a wrong move; you've simply missed a deduction. Step back, re-examine the constraints, and the path forward will reveal itself.

The format is elegant in its predictability. Because the grid is always 7×7 and always holds exactly 10 mines, you know the total "weight" of the puzzle from the start. This lets you reason globally in a way Minesweeper never allows: if you've confirmed 7 mines, exactly 3 more hide somewhere in the remaining cells. That meta-reasoning — tracking placed versus remaining mines — is a technique unique to Tentaizu.

Tentaizu also differs from Minesweeper in a fundamental structural way. In Minesweeper you uncover cells to reveal numbers, progressively exposing the board. In Tentaizu all clues are visible before you make your first move. The entire constraint system is laid out in front of you, turning the puzzle into a pure constraint-satisfaction problem — closer in spirit to Sudoku or nonograms than to mine-clearing action. You're not exploring an unknown board; you're solving a logical equation.

The result is a puzzle that is simultaneously faster and deeper than Minesweeper. A beginner might spend 10–15 minutes untangling a hard configuration; an experienced solver can finish in under 90 seconds. The same puzzle genuinely challenges both patience and pattern recognition. Add the daily format — a fresh puzzle every 24 hours, a global leaderboard, a score to beat — and Tentaizu becomes the kind of daily ritual that's hard to skip.

A Brief History of Tentaizu

Tentaizu appeared in Japanese puzzle magazines in the late 1990s and early 2000s, published alongside formats like Slitherlink, Hitori, and Akari by publishers such as Nikoli. Its tiny footprint — the entire puzzle fits on a postage stamp — made it a popular filler format: simple enough to explain in a single sentence, yet deeply satisfying to crack.

Digital versions spread through Japanese casual gaming sites during the 2000s. After the daily-puzzle renaissance sparked by Wordle in 2021, Tentaizu found a second life as a near-perfect daily puzzle: compact, self-contained, uniquely solvable, and completable in minutes. Unlike word puzzles, Tentaizu needs no translation — the logic is universal.

2008–2009: The puzzle appeared regularly in Southwest Airlines' Spirit magazine, distributed to passengers on Southwest flights. This introduced the game to western audiences and helped build its following outside Japan.

How Tentaizu Differs from Minesweeper

• All clues are visible from the start. You never click to reveal a cell — the numbers are pre-placed and the whole puzzle is visible immediately.
• No guessing, ever. Standard Minesweeper can force a 50/50 guess; Tentaizu is always fully deducible. Every legitimate Tentaizu puzzle has exactly one solution reachable through logic.
• Fixed mine count. Knowing there are always exactly 10 mines lets you reason globally about remaining placements — a powerful constraint Minesweeper's variable boards don't offer.
• Click to flag, not to reveal. Instead of uncovering cells, you cycle unknown cells through states: mine flag → safe mark → unknown. The board never changes; only your annotations do.
• Small, focused, daily. The 7×7 grid and fixed 10 mines create a manageable, repeatable format ideal for a daily puzzle habit.

Quick Strategy Tips

1. Track remaining mines. You start with 10. As you flag mines, watch the counter — fewer remaining mines means tighter constraints on open areas.
2. Start with zeros and eights. A 0 clue means all eight neighbors are safe — mark them. An 8 means all eight neighbors are mines — flag them all instantly.
3. Satisfied constraints unlock neighbors. When a numbered cell's mine tally is fully flagged, every other unknown neighbor is definitively safe.
4. Compare overlapping clues. Two adjacent clues that share neighbors reveal hidden information through subtraction — a core Tentaizu technique.
5. Corners and edges first. Corner cells have only 3 neighbors; edge cells have 5. Their clues are the most constrained and often the easiest to resolve early.

Read the full strategy guide →