yasd

[MobRules]

Yet another stupid death.

My mage was surrounded, out of mana, and low on hit-points. So, I went to activate my staff of teleportation. Wait, why do I still have the staff of cure light wounds? I squelched it. And where did my staff of teleportation.... oh no. Don't tell me I... *headdesk*

[Mondkalb]

You can unsquelch things with "K".

[MobRules]

You can unsquelch things with "K".

Yes, but by that point it wasn't nearby (might have even done the squelching on the previous level), and in a deadly no-win fight

Discovering at some random point that I had accidently squelched the wrong staff would have been annoying. But discovering it while surrounded, out of mana, and very low on hitpoints.... Like the title says, yasd

[Thraalbee]

You can attempt to cast a spell with 0 mana. It may work even though you are likeky to faint and drain a stat

[Pete Mack]

More specifically, you are likely to lose a base point of Constitution. But it's better than just dying.

As a mage, in particular, I like to play extreme sniper/diver. I keep a mental list of high EXP/low danger monsters for every depth. Then dive and search them down, very carefully.
Wolf, bullroarer, low level hounds, young and mature dragons, weak higher demons...
(Bullroarer is in there because he has so few HP. Take him with !hero and a stack of oil and ?Phase door.)