Your walls were no match for me.
My party and I were once shrunk and trapped in a magical adamant strongbox.
It was warded against magic from the inside so we could not port out, and we would all die within the hour due to oxygen running out.
The penalties against the box were far too great given our current state.
So I devised the following plan:

My character takes out piece of chalk and begins to draw on the walls.
He numbers the walls 1, 2, 3, and finally 4.
In succeeding this, he then states the following:
"I make a d20 strength check to break the 4th wall."

They call him mad of course, but he just scored natural 20.