amulet of life saving

One of the more useful NetHack amulets -- you'll usually want to wear this amulet or an amulet of reflection. Its function is simple: if you die, you don't die. The amulet disintegrates afterwards.

An irritating thing about these amulets is that nymphs and some other enemies are sometimes wearing them. You'll only find this out after you kill them and and you see

"Suddenly, the water nymph's amulet begins to glow...--more--"

and by then it's too late; the amulet is wasted. The only good way I can think of to get an amulet of life saving from another monster intact is to polymorph it into a worm or something else that cannot wear amulets -- the amulet would then fall to the floor and you could grab it.

Polymorphing into a metallivore and eating the amulet has no effect.

This useful amulet also exists in ADOM, and has the same effect (it resurrects anyone who dies while wearing it). However, amulets of life saving are much rarer in ADOM than in Nethack, and also much easier to lose. In Nethack, once you are wearing an AoLS, the only way you are likely to lose it (other than dying) is if a nymph steals it. In ADOM, it is vulnerable to being destroyed by traps, like any other non-artifact item.

In Nethack, it's not generally considered worth wishing for an AoLS, because there are many other things (like gray dragon scale mail) which are more important. In ADOM, an AoLS is necessary to save Khelavaster, the dying sage, from certain death, which is compulsory if you're trying to become an Avatar of Order or Balance or an Ultimate Chaos God, and useful even if you're not, because you'll get a nice reward. It is therefore a good idea to wish for one and not wear it but leave it somewhere safe until you're ready to give it to Khelavaster.

In ADOM, it is possible to die while wearing an amulet of life saving by standing on an altar - the amulet won't save you from being sacrificed by a properly aligned intelligent monster.

This happened to me once with a particularly nice character and made me smash a window with my fist, growling in anger. (I had identified with my Troll somewhat.)