Can you build stairs on rock?

I am pretty new to this game and just started playing with some friends. They built a nice tall tower surrounded by rock. I logged on just now to find myself dead, I run to the tower and see someone built stairs on the rock next to to the building to the top. Can you do that? I mean they obviously did, but is it some exploit? I tried building a wood foundation on a flat rock and it wouldn’t let me, is there some trick?

Stairs need a foundation and Pillars.You cant build stair whereever you want.
So sometimes its possible to build a Foundation really nearby a Rock with Pillars.But at the most time you build it in the Rock,you cant places Pillar in the Corners

Alright, I guess they just got lucky on placing the foundation on the rock because it is on the rock right next to the building :frowning:

i placed a foundation part way through a rock. when i was placing pillars/walls i couldnt see them place but i knew they did cuz my # dropped. so u can but not always.