Mate in 1 puzzles

A king in check has exactly three escapes: it moves to a square nothing attacks, the checking piece is captured, or a piece steps in between. Checkmate is a check that closes all three doors. That makes a mate in 1 a matter of bookkeeping more than inspiration: you are not looking for a beautiful move, you are looking for the one check that leaves no answer.

Very often the doors are closed by the king's own pieces. In the first diagram the pawns on f7, g7 and h7 shelter the black king from the front, and lock it in from behind. Re8 gives check along the back rank, f8 and h8 are on the rook's line, and nothing can take the rook or step in front of it. That is the back rank mate, one of the mates you will meet most often in real games, on both sides of the board.

List every check you can give, including the ones that put a piece en prise. In a mate in 1 that costs nothing: if the check is mate, whatever it hangs no longer matters. Then put each check through the questions, in order.

• Squares. Count the king's flight squares. Each one is either attacked by your pieces, occupied by its own, or free. One free square is enough to make the check harmless.
• Capture. Is the checking piece defended? A queen right next to the king is mate only if something protects it, otherwise the king simply takes it.
• Block. A check from a distance can be blocked on any square in between. A check from a knight, or from a piece standing next to the king, cannot.

In the second diagram the queen goes to g7, beside the king. From there it covers f8 and h8, the pawns on f7 and h7 fill the other squares, and the king cannot take on g7 because the pawn on h6 protects it. Squares, capture, block: three noes. The rook on a8 is not decoration either. Without it, Qd8 would be mate too.

Knight checks skip the third question altogether: nothing can be put in front of a knight. When the king is walled in by its own pieces, a single knight is enough, and that is the smothered mate. In the third diagram the rook on g8 and the pawns on g7 and h7 fill every square around the black king. Nf7 gives check from a square that neither the rook nor the king can reach, and the game is over.

When you look for checks, then, give knight checks a second look even when they seem to do nothing. A king in the corner with its own pieces next to it is the position where they do everything. The same goes for the corner mate and Anastasia's mate, where a knight takes the squares a rook or queen cannot.

The puzzles on this page come from real games on Lichess, with Lichess's own rating, easiest first. Any move that gives checkmate counts as solved, even when it is not the one the game saw. Once the final move comes to you without counting, the next step is the mate in 2: the same three questions, asked one move earlier, about a check that is not mate yet.