# Yet Another Stupid Death
Yet Another Stupid Death (commonly abbreviated to YASD) is used when a player has done something, usually avoidable, that leads to his or her demise. Common YASDs in NetHack include:

Hitting a floating eye in melee combat, then getting nibbled to death by a newt while paralyzed
Attempting to engage melee combat with very low HP left
Being killed by a water demon or water moccasin after quaffing from a fountain in hopes of getting a wish
Not noticing that your character has gotten weak from hunger, then being attacked when he/she faints
Not noticing that your character is satiated, then greedily eating a corpse for intrinsics and choking
Touching, eating, fighting bare-handed, or otherwise manipulating a cockatrice, its corpse, or its egg
Drowning in water or lava
Genociding oneself
Eating rotten food after recently praying
Eating something you shouldn't eat (Medusa's corpse—"hey, there's a melon on the ground!")
Zapping a wand of death (or some other powerful ray) at a wall and getting hit by the reflection
Wandering near a known giant eel or kraken
Death by boredom
Kicking and injuring your foot resulting in death due to low health
Falling off your Knight's starting pony after attempting to ride it at XL 1
Wishing for a cross-aligned artifact, and having it blast you to death
Forgetting about the power of Elbereth
Dying in possession of an identified amulet of life saving, but not wearing it simply because you forgot to put it on
Forgetting that you have low health when restoring a save file and immediately starting to explore
Some players distinguish YASD from YAAD (Yet Another Annoying Death), using YAAD or DYWYPI for random, unavoidable events such as falling onto poison spikes (provided the pit wasn't already known, of course) or an encounter with a Gnome With the Wand of Death, and reserving YASD for pilot error. The dividing line depends on the player; to an expert, almost all deaths are avoidable YASDs.
Amusingly enough, YASDs can happen to monsters as well, such as bouncing a beam off a wall back at themselves.

See also
Lessons learned the hard way
Bad Idea