Curse items is one of the most despicable monster spells in NetHack. It can be cast in melee range by monsters such as liches, or encountered in other ways. It will unbless or curse a number of your inventory items, which can reduce their effects or make them dangerous and difficult to remove.
The spell will normally affect 1d6 random items in your inventory if it succeeds; blessed items will become uncursed and uncursed items will become cursed. If you have half spell damage or magic resistance, only 1d3 items will be affected; if you have both, only 1d2 will be affected.
Additionally, despite not being in your inventory, a saddle has an independent 1⁄4 chance of being affected.
While containers can themselves be cursed by this spell, their contents cannot. But a bag of holding becomes much heavier if cursed, and using a cursed bag of holding risks destroying some objects inside. Most players using one will learn the remove curse spell or carry a blessed scroll of remove curse, potion of holy water, or a wand of cancellation in an oilskin sack or a (greased) plain sack. A less preferable alternative is to temporarily stow the bag of holding in a non-magical bag while fighting liches—even if the outer bag gets cursed, the bag of holding will be safe.
To minimize the negative effects of this spell, you can bless even those items in main inventory that are not intrinsically improved by being blessed (such as armor). Another tactic involves filling up inventory slots with individual items that are light and easily obtainable in large numbers (such as arrows, darts, and gems), each given a different name so that they will not stack together. Since the cursing effect randomly chooses items from inventory, this reduces the chance that a valuable item will be hit.
If you wield a two-handed weapon, you should plan ahead in case monsters curse your weapon, e.g. deposit some holy water in the floor in strategic places. Keep it always blessed and make sure it's safe to pray.
Some items are better cursed, and a monster might do you the favor. To use this, you can deliberately get affected by this in a controlled manner. Drop, bag, or stash everything you wouldn't want cursed. Use one of the weaker monsters that can cast this, and confine it into a small space with Elbereth or boulders. You may want to set this up on an early dungeon level, where other generated monsters are less dangerous.
- Praying: one possible bad effect is a malignant aura.
- The Wizard of Yendor: Once he is dead or the invocation ritual has been performed, various effects will occur at random intervals. One of these effects will curse your items.
- Sitting on a throne with zero or negative Luck can produce a curse effect.
- "You feel as if you need some help."
- The spell was cast by an adjacent monster
- "You notice a black glow surround you."
- The spell was cast remotely by the Wizard of Yendor.
- "A black glow surrounds you."
- The spell is punishment from a god.
- "You feel a malignant aura surround you."
- Some random inventory items were cursed.
- "You feel a malignant aura surround the magic-absorbing blade."
- The curse was absorbed by Magicbane.
- "<artifact> resists!"
- An intelligent artifact resisted being cursed. Will be displayed for each resisting artifact.
In UnNetHack, if curse items targets an already-cursed container, one random item inside it is cursed instead. This can theoretically happen recursively if you have nested cursed containers. If you are double-bagging to protect your bag of holding, it is important that the bag containing the bag of holding remains non-cursed.