The Ninth Floor of the Tower of Babylon was called the Floor of Partings.
The reason for this name was that when the tower just opened, this floor had been a turning point for most of the players who challenged the tower.
This was the floor that many people hated, especially if they came to the tower in groups of two or more. The reason? The trial of this floor required a party to fight against each other.
If the party had two members, only one of them would proceed to the next floor. If the party had six, three of them would pass.
What happened if the group was an odd number? That was the worst part. If there were three people in the group, only one of them could pass. If there were five, only two of them would pass.
For a group of seven, only three could proceed to the next floor.