This page is a list of things that people might commonly wish for that they really shouldn't. If you've wished for it (not just to see if anything happens), and if it wasn't worth the wish, it could belong here.

Wish name Why not to wish for it Notes
Satiation Wishing for stomafillia herbs results in much more satiation The only time you should wish for this is if you do not have time to eat (due to monsters etc), yet are starving
Banshee (or Sheep) Unless the PC has their ears plugged, wishing for a banshee will result in instant death. Can be exploitable if the PC is well-prepared.
Death Unnaturally ages the PC to the point of death. This is the only known non-lethal way to find your exact age limit in game. Have lots of potions of youth handy.
Corpses Corpses of specific monsters (eg. giant slug corpse) cannot be wished for. Instead the appropriate monster will be spawned. Corpses without specification can be wished for and results in random corpses dependent on DL.
Godhood Tells you "THOU SHALT NOT MOCK THE CREATOR", and does nothing.
Healing There are generally better ways to heal your PC. In a situation of absolute desperation, this could save the PC's life. The Healing skill cannot be wished for.
Alertness Raises the PC's perception instead of giving the Alertness skill. The Alertness skill cannot be wished for.
Any Artifact Artifacts cannot be wished for.
Rings of djinni summoning Wishes cannot be wished for. Produces brass rings.
Wands of wishing Wishes cannot be wished for. Produces wands of wonder
Spellbooks of Wish Wishes cannot be wished for. Produces Spellbooks of Calm Monster
Crumpled scroll Cannot be wished for. Produces Blank scrolls
Any Intrinsic Intrinsics cannot be wished for. Will typically produce a ring/amulet that has a similar effect. Consider wishing for bracers of resistance instead.
Prefixed or suffixed equipment Prefixes and suffixes cannot be wished for, but items that are wished for may carry prefixes or suffixes. Exceptions: items that are "naturally" prefixed/suffixed such as most slaying ammo, whips of slaughtering, etc.
Moloch armor Produces eternium plate mail instead Wishing for an emperor moloch, which results in about 20 greater molochs beings summoned, will likely provide this armor if the PC can survive the fight.
Potions of youth Potions of longevity have a larger average effect on time to live. If the player desires to undo the stat modifications of aging, youth may be needed.
Weapons of any kind Generally, wishing for weapons is considered inferior to wishing for armor. There are a number of strong artifact weapons available early in the game, and the Darkforge treasury often offers some excellent weapons as well, whereas finding high-end shields or armors is more difficult early on, and added protection is more likely to keep the PC alive than a better weapon. The only weapons generally worth considering are maces of destruction, swords of sharpness, phase daggers, whips of slaughtering, or possibly some eternium weapons.
Most unique NPCs Generally, unique NPCs cannot be wished for. In the rare event they can be wished for (e.g. Demented Ratling), they will not act like a "normal" NPC would
Thomas Biskup Tells you "THOU SHALT NOT MOCK THE CREATOR", and does nothing.
Immortality Tells you "Funny, very funny.", and does nothing.
Mindcraft Gives Woodcraft skill instead.
Light Lights the area around, grants wand of light
Babes Produces "We are feeling lonely, aren't we?"
Gold Grants 2500+ gold per PC's level
Glod baffled small dwarf named Glod appears