Final position — Black is winning
Lasker Trap #3
Black wins in 12 moves with a decisive material gain. (Traps - Chess Traps - Lasker Trap - D08 - https://lichess.org/@/gambits2pieces)
The moves
| 1. | d4 | d5 |
| 2. | c4 | e5 |
| 3. | dxe5 | d4 |
| 4. | e3 | Bb4+ |
| 5. | Bd2 | dxe3 |
| 6. | Bxb4 | exf2+ |
| 7. | Ke2 | fxg1=N+ |
| 8. | Ke1 | Qh4+ |
| 9. | Kd2 | Nc6 |
| 10. | Bc3 | Bg4 |
| 11. | Be2 | O-O-O+ |
| 12. | Kc2 |
How the Lasker Trap #3 works
The Lasker Trap #3 is a classic chess opening trap arising from the Queen's Gambit. In this line Black wins decisive material by move 12, punishing a natural-looking but losing idea from White.
The full sequence runs 1.d4 d5 2.c4 e5 3.dxe5 d4 4.e3 Bb4+ 5.Bd2 dxe3 6.Bxb4 exf2+ 7.Ke2 fxg1=N+ 8.Ke1 Qh4+ 9.Kd2 Nc6 10.Bc3 Bg4 11.Be2 O-O-O+ 12.Kc2. Each move looks reasonable, which is exactly why the trap is so effective over the board — White walks into it while trying to play "normal" developing moves.
This pattern is well known from master and correspondence play (Traps - Chess Traps - Lasker Trap - D08 - https://lichess.org/@/gambits2pieces). Recognising it early lets you either spring it as Black or sidestep it as White.
Practice this trap move-by-move
Open the Lasker Trap #3 in the Trapsterapp to play it out on a live board, drill it in practice mode, and learn how to avoid it when it's set for you — along with the full library of chess traps and gambits, fully offline.