This is the forum for helping you out if you're stuck or if you want to discuss the nitty gritty details of the dungeons within Mount Grimrock. Warning: forum contains spoilers!
I try to open cell with "Armor" inside. Found hint-note
"Stand where shadows of torches cross ..."
See 3 slots for torches in the walls, but have only two torches
Can I solve this room with two torches only ?
Well, you can try with throwing the rocks everywhere like a mad man, or try to calculate where you think it's gonna be the shadow (it's not that hard, if you need some help check other rooms with torches to see how does it "move"). But yes, it can be done with 1, 2, 3 or without torches, the only thing that changes is the "difficulty" to find the right square.