A
NetHack tool that is much more useful than a
stethoscope. Aside from producing
humorous messages, applying it in the direction of a
monster has an 80% chance of
scaring the monster for 2 to 8 turns (as long as the monster can see the mirror and itself, i.e. has
eyes and is not
blind or
invisible). This does not function against
unicorns or
humanoids.
Applying a mirror against monsters that have gaze attacks has predictable and very useful effects. Notably, showing the mirror to Medusa will turn her to stone, as well it should. Floating eyes can be paralyzed and umber hulks confused in this manner. A nymph or succubus will steal the mirror if you show it to them.
If the mirror is cursed, it has a 50% chance of failure in any case. Nymphs usually carry mirrors (and potions of object detection...gee, I wonder what they could be up to). Mirrors can be broken by any application of force; in particular, the force bolt spell and kicking will break mirrors. If you break a mirror, you will suffer a luck penalty.