# The Double-Spiral Staircase

Imagine a conventional enclosed spiral staircase, of the type you might find in a castle. You have a hollow cylinder, with spiral stairs running up through the middle. For each 360 degrees that the spiral turns, it rises one level. So, if you enter through a door on the south side on level 1, 360 degrees of climb later, you can exit onto level 2 though another door on the south side (directly above the door on level 1).

The double-spiral staircase, by contrast, has a larger cylinder, such that the spiral only needs to go through 180 degrees to climb one level. So if you entered through a door on the south side on level 1, the door to level 2 would be on the north side (the opposite side of the cylinder). If you carried on climbing until the spiral had made one complete turn, you would find yourself by the door to level 3.

So, if there were 6 floors, the exits to levels 1, 3, 5 would be on the south side of the cylinder, whilst the exits to levels 2, 4 and 6 would be on the north side.

Still with me?

Good. Because here's where we get to the interesting bit.

With this sort of spiral, there is room to fit in a second spiral in the same space, identical to the first, but rotated through 180 degrees. (Imagine the double helix of DNA).

In our example, the first spiral was reached through a door on the south side of the cylinder. Well, if you walked round the outside of the cylinder, you would find another door on the north side of the cylinder, which would lead to a totally separate spiral staircase. This staircase would have exits to levels 1, 3 and 5 on the north side of the cylinder, and exits to levels 2, 4 and 6 on the south-side.

## Where Did I Find Out About It?

I was reading something about an old English country house, which had at its centre a double-spiral staircase.

One of the staircases was for the residents and guests. The other was for the servants. (So that the guests didn't have to risk bumping into the staff, with all the need for forces and awkward politeness that this would entail).

## What Could You Do With It?

Firstly, you could confuse the players. "Didn't this staircase used to have a blue carpet?"

(In the above example, the resident's staircase would probably have sumptuous fittings. By contrast, the servant's staircase would probably be quite plain and simple.)

Or...

"You start at the top and work down, and we'll start at the bottom and work up - and meet in the middle."

Secondly, you can impede navigation. It might be that whole portions of a level are only accessible from one of the staircases.

Again, in the above example, the kitchens might only be accessible from the servant's staircase.

Have fun.