Ruy Lopez, Noah's Ark Trap

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

Position after 11...c4. The white king bishop is trapped.

The Noah's Ark Trap is a chess opening trap in the Ruy Lopez. The name is actually used to describe a family of traps in the Ruy Lopez in which a white bishop is trapped on the b3-square by black pawns.

Discussion

The origin of the name is uncertain. The shape of the black pawns on a6, b5, and c4 may resemble an ark, or the name may suggest that the trap is "as old as Noah's Ark".

Even chess masters have occasionally fallen victim to this trap. An example is a game between Endre Steiner and José Capablanca at the Budapest tournament in 1929:

1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 d6 5. d4

Better moves for White are 5.c3, 5.Bxc6+, and 5.0-0.

5... b5 6. Bb3 Nxd4 7. Nxd4 exd4 8. Qxd4??

Alexander Alekhine recommended this move in the tournament book for New York 1924 as a means for White to draw, but it is a mistake that loses material. White should instead play 8.Bd5 or try a gambit with 8.c3.

8... c5 9. Qd5 Be6 10. Qc6+ Bd7 11. Qd5 c4 (see diagram)

The white king bishop is trapped. White resigned after 32 moves.

In the Sicilian

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

Position after 4.Ba4?? b5 5.Bb3 c4

A variation of this trap can occur in the Sicilian Defence after the moves

 1. e4 c5 2. Nf3 Nc6 3. Bb5

The Rossolimo Variation.

 3... a6 4. Ba4??

4.Bxc6 is necessary and the point of 3.Bb5 itself.

 4... b5 5. Bb3 c4 (see diagram)

And the bishop is similarly trapped.