I've heard the following story, which or may not be true:
We all know the touch-rule move, where if you touch a piece you must move it. But what if you touch a piece that can't move? Well, apparently the old rules stated that you would then have to move your King. At a tournament one day, 1.e4 d5 2.exd5 Qxd5 was played. White went to grab his Knight, but he accidentally grabbed the piece beside it, the Bc1. The Bishop couldn't move, so he was forced to play 3.Ke2, allowing the mate in 1, 3...Qe4#.
We all know the touch-rule move, where if you touch a piece you must move it. But what if you touch a piece that can't move? Well, apparently the old rules stated that you would then have to move your King. At a tournament one day, 1.e4 d5 2.exd5 Qxd5 was played. White went to grab his Knight, but he accidentally grabbed the piece beside it, the Bc1. The Bishop couldn't move, so he was forced to play 3.Ke2, allowing the mate in 1, 3...Qe4#.