Stairs Always Turned Clockwise

Castles were always built with a spiraling staircase that turned clockwise. This was a purposeful design element that served an incredibly practical purpose; the idea was incoming siegers would ascend the stairs, but be given a huge disadvantage in the way of their sword arm, as most people are right-handed. On the other hand, castle occupants descending the stairs would be given the advantage of a staircase designed with their sword-arms in mind. Damned they were though, if they were attacked by an entirely left-handed infantry.