"May your hair fall out and grow boils on your nose, limp with the gout and lose all your clothes. A hex on you!"Curse is a first-level death magic spell in Heroes of Might and Magic IV that costs two spell points and causes the target to always inflict the minimum possible damage in their damage range.
Note that creatures can have quite variable damage ranges. For example, Orcs do 1-3 damage per unit, while Peasants do 2-3 damage per unit. Thus, this spell is far more crippling to a stack of Orcs than it would be to a stack of Peasants.
In fact, not surprisingly, Chaos creatures have the widest damage ranges, and so are most affected by Curse, though this spell is still quite effective against most level 4 units (which tend to have very wide damage ranges, like 30-55), and against fighting heroes.
One thing that makes Curse quite useful is that it is one of the few good curses at Death's disposal that works on virtually anything, for it is not a mind spell, nor does it ravage the body.
If cast on a unit enjoying the effects of the Bless spell, Curse will negate it and leave the unit cursed instead.