Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bb5/3...f5/4. Nc3/4...fxe4/5. Nxe4/5...d5/6. Nxe5/6...dxe4/7. Nxc6/7...Qd5/8. c4/8...Qd6/9. Nxa7/9...Bd7/10. Bxd7/10...Qxd7/11. Qh5/11...g6/12. Qe5/12...Kf7

Ruy Lopez, Schliemann Defence

	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

Common moves:
13. Nb5 - only move

White does not take the rook!

The reason White does not take the rook

Because the queen gets trapped in the corner after 13.Qxh8 Nf6, after which Black can leisurely play ...Rd8, move the bishop, and force White to trade queen for rook. That wouldn't be a disaster for White, who would have two rooks and two pawns for the queen, in fact it's quite possibly a winning advantage still. But White's rooks would be stuck in the corners, and the Black queen would be running around in the middle of the board, and accidents can happen.

The move White plays instead

Is the simple 13. Nb5, saving the knight and hitting c7.