Legal's Mate
Give up your queen and checkmate with three minor pieces: the most famous fake pin in chess.
A quiet start
This trap is named after the 18th-century French player Kermur de Legall. Black develops the light-squared bishop to g4, pinning White's knight on f3 to the queen, and then plays the slow move pawn to g6. Step through the moves.
A pin that is not a pin
The knight on f3 looks stuck: if it moves, the bishop takes the queen on d1. But a pin to the queen is not a law. The knight may still move, as long as what White gets back is worth more than a queen. Here, that something is checkmate.
Spring the trap
Your turn
Ignore the pin. Offer your queen and checkmate the king.
Show the answer
Knight takes e5, bishop takes the queen, bishop takes f7 check, king to e7, knight to d5 mate. Three minor pieces cover every square around the king.
If Black refuses
Your turn
Black spotted the trick and took your knight instead. Collect your reward.
Show the answer
Queen takes g4. You traded a knight for a pawn and a bishop, so you come out a pawn ahead with a fine position.
The final picture
Look at the finished net. The knight on d5 gives check and covers f6. The bishop on f7 covers e6 and e8. The knight on e5 guards the bishop and covers d7. Black's own pieces block d6, d8 and f8. The knight on c3 was the key: without it, nothing could reach d5.
If they don't fall for it
Your turn
Black guarded e5 with knight to c6 instead of playing pawn to g6, so the trick is off. You asked the bishop with pawn to h3, and it took your knight. Take back, then keep developing.
Show the answer
Queen takes f3 keeps your pawns healthy and eyes f7. After knight to f6, castle or bring a knight to the center. You have the two bishops and an easy game.
Check yourself
Question
In the starting position of the trap, which white piece makes the queen sacrifice work?
Show the answer
The knight on c3
Yes. It is the piece that jumps to d5 for the final check. Without it the sacrifice just loses the queen.
More in Openings
Opening principles
Claim the center, develop your pieces, castle, and keep the queen home until it is safe.
The London setup
d4, Bf4, e3, Nf3, c3, Bd3, Nbd2: one calm setup you can play against almost anything.
The Fried Liver Attack
In the Two Knights Defense one natural recapture lets White sacrifice a knight on f7 and drag Black's king into the open.