From check to checkmate

In Chapter 8, we learnt that being in check means your king is under attack. We also learnt that you must respond: move the king, capture the checking piece, or block the attack if possible.

But what happens if you look for all three responses and none of them works?

That's checkmate. When a player is in check and has no legal way to escape, the game is over. The player who gave checkmate wins.

The king is never actually captured. There is no final move that takes it off the board. Checkmate means the king cannot be saved, so play stops there.

Check is a threat. Checkmate is the end of the game.

A queen, a king and one missing escape

Let's start with a small position. White's queen is on g7, Black's king is on h8, and White's king is on f6.

The queen is checking the black king diagonally. Why can't Black simply move away?

• g8 is controlled by the queen.
• h7 is also controlled by the queen.
• g7 contains the queen, but White's king protects her. Black cannot capture the queen there.

Black cannot block this check either: the queen is right next to the king, with no square between them. There is no safe move, capture or block. Checkmate.

What changes if the queen isn't protected?

Move White's king farther away, to e6, and look again:

The queen is still checking. But now Black can capture her on g7 without moving into another attack. That's a legal response, so this position is not checkmate.

A tiny change on the board can make an enormous difference.

Why can't the king escape?

To decide whether a check really is mate, reuse the three questions from Chapter 8:

1. Move: Is there a safe square the king can reach?
2. Capture: Can the king or another friendly piece take the checking piece safely?
3. Block: Can a piece interrupt the checking line, if there is a square between attacker and king?

If even one legal response exists, it is check, not checkmate.

You don't need to memorise dozens of mating patterns to understand this rule. You need to look carefully at where the king can go and what the defending pieces can do.

Back-rank checkmate: trapped by your own pieces

A king often spends much of a game behind its pawns. That can make it safer from an attack — but it can also leave the king with nowhere to run.

Look at the black king on g8, the black pawns on f7, g7 and h7, and White's rook on a8.

The rook checks along the eighth rank. The king cannot move to f8 or h8 because the rook controls those squares. The pawns fill the squares immediately below the king. With no legal capture or block available, this is back-rank checkmate.

Now look at a similar position where the g-pawn has moved forwards:

Black can escape to g7. The rook still gives check, but the open escape square means the game is not over.

A useful early lesson: Pawns protecting your king can be valuable, but a king with no room to move may become vulnerable. We'll return to pawn shelter and king safety later.

Pieces working together

A rook can control an entire rank. But it cannot always cover every square the opposing king might use.

In this position, White's king helps the rook:

White's rook on a8 gives check. White's king on g6 controls g7 and h7, while the rook stops g8. Neither piece does the whole job alone.

A queen and knight can work together too:

White's queen on g7 delivers check, and the knight on e6 protects the queen. That means Black cannot capture her. The queen also controls the king's remaining exits.

This is our first glimpse of piece coordination: one piece gives the check, while another helps take away the escapes. Later, in 2 + 2 = 5: When Pieces Work Together, we'll explore this idea much further.

A check that isn't quite mate

Now compare our rook-and-king example with this one:

The rook still checks along the eighth rank. White's king is on f6, though, and Black can move to h7. That's one legal escape, so it isn't checkmate.

If you're ever unsure, one legal escape is all you need to disprove checkmate.

How to look for a checkmate

When you're looking for a winning move, use this short routine:

1. Find a possible check. Which of your pieces could attack the king next?
2. Imagine the position after that move. Where would the checking piece stand?
3. Look for king escapes. Which squares would still be safe for the opponent?
4. Check captures and blocks. Could the opponent take the checking piece or interrupt its attack?
5. Decide. If the king is checked and no legal reply exists, the move is checkmate.

For now, our examples use only a few pieces so you can concentrate on this process. Real games often have more pieces on the board, but the rule stays exactly the same.

Checkmate Challenge

Let's put those ideas to work. There are two sorts of positions here:

• Checkmate or not? Decide whether the side to move is already checkmated. Look for a legal escape before you commit.
• Mate in one. White moves next. Choose the move that immediately checkmates Black. A move that merely gives check isn't enough.

Use the candidate moves to explore the board before checking your answer. The positions are checked using the same chess rules as our earlier challenges.

What to remember

• Checkmate means the king is in check and there is no legal way to escape.
• The king isn't captured. The game ends, and the player delivering checkmate wins.
• A check isn't mate if the defender can move, capture or block to safety.
• A checking piece is often helped by another piece that protects it or covers an escape square.
• A king trapped behind its own pawns can sometimes be checkmated along the back rank.
• Mate in one means a single legal move ends the game by checkmate.
• Always look for the opponent's legal responses before deciding that a check is mate.

Knowledge check

You've learnt how to recognise checkmate and why a checking move sometimes isn't enough. Let's see what you've understood.

Next: When nobody can move

There's one more important situation to explore. What if a player has no legal moves, but their king is not in check? That isn't checkmate. It's called stalemate, and we'll discover why it means a draw in Chapter 10.