Ring of invisibility
A ring of invisibility is a type of ring that appears in NetHack.
Generation
Nazgul will always generate with a cursed ring of invisibility.[1]
Description
While worn, a ring of invisibility confers invisibility.
Strategy
A ring of invisibility tends to be most useful early on, when most monsters lack see invisible - as a character becomes more adept at combat while developing and identifying their kit, the ring becomes more of a convenience saved for specific combat encounters, though it can be superseded by potions of invisibility that are non-blessed. A character that wants permanent invisibility and has mummy wrappings to spare will usually elect for a blessed potion of invisibility or a wand of make invisible to keep their equipment slots open.
For other characters, the ring can be useful for killing shopkeepers that you plan to rob by taking advantage of their movement patterns.
Encyclopedia entry
"When time came for the shepherds to hold their customary
assembly in order to prepare their monthly report to the king
about the state of the flocks, he came too, wearing this ring.
While he was sitting with the others, it chanced that he moved
the collet of the ring around toward himself into the inside of
his hand; having done this, he disappeared from the sight of
those who were sitting beside him, and they discussed of him as
of someone who had left. And he wondered and once again feeling
for the ring, he turned the collet outwards and, by turning it,
reappeared. Reflecting upon this, he put the ring to the test
to see if it indeed had such power, and he came to this
conclusion that, by turning the collet inwards, he became
invisible, outwards, visible. Having perceived this, he at
once managed for himself to become one of the envoys to the
king; upon arrival, having seduced his wife, with her help,
he laid a hand on the king, murdered him and took hold of the
leadership."
