Légal Trap
C41 · Played as white · Beginner · Traps & Tricks
Hang the queen on purpose and mate with three minor pieces
Also known as Legal's Mate, Blackburne Trap, Legal Trap.
The main line
1.e4 e5 2.Bc4 d6 3.Nf3 Bg4 4.Nc3 g6 5.Nxe5 Bxd1 6.Bxf7+ Ke7 7.Nd5#
Strategic ideas
- Punish an early …Bg4 pin that isn't backed up by …Nf6 or …Be7
- Break the pin by simply ignoring it — Nxe5 offers the queen and wins
- Mate with bishop and two knights while the black queen sits at home
- Learn the most famous queen sacrifice in beginner chess, from the 1750s
- Understand the defence: …Bg4 needs support before White can be punished for Nxe5
Key themes
- Attack — Every white piece converges on f7 and e7 while Black's queenside sleeps
- Tactics — The whole line is one forcing sequence built on a deliberately unsound-looking queen sacrifice
- King Safety — Black's king never gets out of the centre, and three minor pieces are enough to finish it
Typical plans
Sire de Légal was playing this in Parisian cafés before the French Revolution, and it still catches people every single day. The pin on the f3-knight looks binding, so White breaks it by ignoring it: Nxe5 hangs the queen, and if Black takes, three minor pieces deliver mate on move seven. The lesson underneath the trick is real — a pin isn't absolute, and …Bg4 needs backup before it's worth anything. Black's escape is simply …Nxe5, coming out a pawn down but alive.
Move by move
- e4 — White claims the centre.
- e5 — Black meets it symmetrically.
- Bc4 — White develops toward f7, the classic target.
- d6 — Black shores up e5 solidly — a Philidor-style setup.
- Nf3 — White develops, attacking e5.
- Bg4 — Black pins the knight against the queen. This looks strong, and it's played without any support — that's the whole problem.
- Nc3 — White develops and quietly ignores the pin.
- g6 — Black plays a natural-looking move, preparing …Bg7. It's also the last quiet moment in the game.
- Nxe5 — White takes the pawn and simply lets the queen hang. The f3-knight was pinned to it — but a pin is only binding if taking the queen is actually good, and here it isn't.
- Bxd1 — Black takes the queen. This is the losing move: …Nxe5 was fine and just leaves Black a pawn down. Greed decides the game.
- Bxf7+ — White gives check and drags the king out. Material is a queen down for two pawns — and it makes no difference at all.
- Ke7 — Black's king must step to e7 — the only legal square.
- Nd5# — White mates. The knight on d5 covers the escape, the bishop and knights do the rest, and White is a queen down at the moment of checkmate. Légal's Mate, unchanged since the 1750s.
Where the line leads
White's plans
- Only play Nxe5 when the black bishop on g4 is unsupported — otherwise it's just a blunder
- Follow up with Bxf7+ and Nd5 — the mate is forced once Black takes the queen
- If Black declines with …Nxe5, take the pawn back and enjoy a small edge
Black's plans
- Don't take the queen — …Nxe5 keeps the game going, a pawn down but perfectly playable
- Support the …Bg4 pin with …Nf6 and …Be7 before it's worth anything
- Remember that a pin on a knight defending nothing critical is not a real pin
Légal Trap FAQ
- What are the moves of the Légal Trap?
- The Légal Trap (C41) runs 1.e4 e5 2.Bc4 d6 3.Nf3 Bg4 4.Nc3 g6 5.Nxe5 Bxd1 6.Bxf7+ Ke7 7.Nd5#. It is played from White's side of the board.
- What is the idea behind the Légal Trap?
- Hang the queen on purpose and mate with three minor pieces. In practice that means: Punish an early …Bg4 pin that isn't backed up by …Nf6 or …Be7; Break the pin by simply ignoring it — Nxe5 offers the queen and wins; Mate with bishop and two knights while the black queen sits at home.
- Is the Légal Trap good for beginners?
- Yes — it is rated Beginner here, which means the moves follow from a handful of ideas rather than from memorised theory.
- What are the plans after the Légal Trap?
- White: Only play Nxe5 when the black bishop on g4 is unsupported — otherwise it's just a blunder. Black: Don't take the queen — …Nxe5 keeps the game going, a pawn down but perfectly playable.