Stoning

Stoning resistance is a resistance that can not be gained by external means but only by polymorphing into an intrinsicly stoning resistant monster.

Stoning resistant monsters
The most obvious stoning resitant monsters are cockatrices and monsters already made of stone, such as gargoyles. In addition to those, all elementals, xorns, all but blue jellies, yellow dragons, green molds, wraiths, skeletons, lizards and all monsters represented by letters v, y and P are stoning resistant. If you try to stone golems, they turn to stone golems instead.

Stopping stiffening
If you are bitten by a cockatrice and start turning to stone – stiffening – you still have several ways, albeit not several turns, to save yourself. Eating a lizard or any acidic monster stops the process. They are the ones represented by letters colon, b, j, D, F, N and P. The standard method of these is to eat a lizard corpse, since they never rot and can, and should, thus always be carried along!

However, if you do not have a lizard corpse with you, you may quaff a potion of acid. This works whereas the acidic corpses too. The stone to flesh spell will also save you if you cast it to yourself, but it will also turn your items made of stone into meat, including rocks, rings and wands.

An amulet of unchanging will not protect you from stoning.