The Lasker Trap is a chess opening trap in the Albin Counter Gambit, named after Emanuel Lasker. It is unusual in that it features an underpromotion as early as the 7th move.

The Albin-Counter Gambit begins with the moves

1.d4 d5

2.c4 e5

3.dxe5 d4

The Black pawn on d4 is stronger than it appears.

4.e3?

Careless. Usual and better is 4.Nf3.

4... Bb4+

5.Bd2 dxe3!

(See diagram.) Now White's best option is to accept weak pawns with 6.fxe3.

6.Bxb4??

Blundering into the Lasker Trap.

6... exf2+

Now 7.Kxf2 would lose the queen to 7...Qxd1, so White must play 7.Ke2.

7.Ke2 fxg1=N+!!

Underpromotion is the key to the trap. Instead 7...fxg1=Q 8.Qxd8+ Kxd8 9.Rxg1 is OK for White. Now 8.Rxg1 Bg4+ wins White's queen, so he must move the king again.

8.Ke1 Qh4+

If White tries 9.g3 then 9...Qe4+ wins the rook on h1.

9.Kd2 Nc6

White is hopelessly lost. After 10.Bc3 Bg4 followed by 11...0-0-0+ is crushing.

References