Stairs in medieval fortifications were constructed to contain trick or stumble steps. These were steps that had different rise height or thread depth from the rest and would cause anyone running up the stairs to stumble or fall, so slowing down the attackers’ progress.

Stairs in medieval fortifications were constructed to contain trick or stumble steps. These were steps that had different rise height or thread depth from the rest and would cause anyone running up the stairs to stumble or fall, so slowing down the attackers’ progress.