Mysteries
on the board
Three puzzle families with a single right answer, an ELO that shifts every move, and a ranking that never forgets who rules.
See how each mystery is cracked
Three families, three distinct logics. If this is your first time, read the explanation next to the animation: every step teaches you what to look for — and what to avoid — before your first attempt.
Queens: zero captures
In this mode you get an NxN board with a few queens already placed. Your job is to drop the remaining queens onto empty squares so that none of them can capture another.
The queen is the strongest piece in chess: she attacks her entire row, her entire column and both diagonals with no range limit. That means two queens can never share any of those lines. Whenever you place a queen, mentally sweep all four directions — if a line crosses another queen, the placement is invalid.
To play, tap or drag a queen from the reserve onto a free square. If you make a mistake, take her back and try a different square. Each puzzle has exactly one valid layout, so once every queen coexists without threatening another, the mystery is solved.
Tip: start with the most constrained rows or columns. Squares that only accept a single possible queen are your best foothold; the rest falls into place by elimination.
Knight: one continuous tour
Here you only have one piece: a knight. You must move it until it has stepped on every free square of the board exactly once, never repeating a square and never landing on a blocked square (the striped ones).
The knight moves in an L-shape: two squares in one direction and one square perpendicular. It is the only piece that leaps over obstacles, but blocked squares are still off-limits as a destination. Every jump has to land on a free square you have not yet visited.
To play, tap the next square you want to jump to. If it is within the knight’s range and not yet visited, the move is accepted and the square is marked with its order number. The header counter shows how many squares are left to cover.
Tip: favour jumps into corners and squares with few exits. If you leave an isolated square for the very end, you will run out of legal moves before reaching it.
Minesweeper: match the numbers
In this mode the board ships with several numbers visible. Each number tells you how many pieces must be attacking that square when the puzzle is solved. Your reserve contains a handful of pieces (bishops, rooks, knights, queens, pawns or kings); you spread them across the empty squares until every clue matches its attacker count exactly.
Remember each piece’s range: bishops attack diagonals, rooks attack rows and columns, queens combine both, knights leap in L-shapes, the king threatens all eight adjacent squares, and the pawn threatens only its four diagonal neighbours (here pawns are colour-blind and attack in every diagonal direction). A piece never attacks the square it stands on.
Long-range pieces (bishop, rook, queen) get blocked by anything in their path: the ray stops on the first piece it hits and goes no further. In the animation the bishop’s diagonal is intercepted by the pawn — the bishop never reaches the clue. Knights leap over blockers; pawns and kings are short-range, so blocking does not apply to them.
To play, tap a piece from the reserve and then a free square — or drag it directly. Clues turn green once their attacker count matches; if there are too many or too few attackers, the number stays red.
Tip: start with the smallest numbers. A 0 forces the squares around it to stay empty, and a 1 drastically narrows down where the attack can come from. Save the higher numbers for the end, once most of the board is already settled.