From IFWiki

Possible uses

  • Looking in mirrors is often used as a synonym for EXAMINE ME. If X ME doesn't give much by way of physical description, a mirror may be able to add more detail. If you have amnesia, this becomes doubly valuable.
  • Mirrors can be used to look around corners, or combined with lenses to form periscopes.
  • Light reflected from a mirror can be used as a signalling device, to blind an enemy, or to light an area.
  • Mirrors can deflect harmful beams, such as lasers.
  • Some mirrors may be one-way, and enable you to see things without them seeing you.
  • As a very weak form of encryption, you may discover notes in mirror-writing; you could laboriously decipher this by hand, but it would be much easier to look at them in a miror.
  • Placed on walls, large mirrors may make rooms appear larger, or appear to be passageways that don't exist. A hall of mirrors can form a very difficult maze.
  • Some creatures mistake their own reflection for an enemy, and will attack it.
  • Mirrors are often the vulnerability of monsters with deadly gazes, such as the basilisk, cockatrice or Medusa. Either the gaze will have its full effect in a mirror (in which case the gaze can be turned back upon it), or it won't (in which case this is a safe way to watch the creature).
  • Various monsters, such as vampires, can be identified by their lack of reflection in a mirror.
  • Mirrors may serve various magical purposes: here are a few of the more common.
    • Magical portals. These may lead to mirror-worlds in which everything is inverted or to another mirror, providing a method for creating player-chosen short cuts. (If both mirrors were carryable items.)
    • Communication devices, or fantasy CCTV.
    • The reflection in some magic mirrors may show your true self, your greatest desire, yourself in the past or future, or similar significant information.
    • Duplicators.
  • Most mirrors are made of glass; bad luck or not, if you're in need of a cutting implement you could always break one.
  • Laid horizontally, mirrors form a flat, even, smooth surface on which everything can be seen easily.
  • If a detector beam uses a reflector on the opposite wall, it can be tricked into thinking the beam has not been broken by placing a mirror in front of it.
  • Placed strategically, a large mirror can be used to make someone appear to be at the end of a corridor when they are really around the corner (and so a bullet or charging animal will go through the mirror - possibly into another object - instead of hitting the person).

Substitutes and likely sources

  • Some objects can be polished to make a mirror like surface (such as a shield or a piece of tin).
  • Most cars come with mirrors inside and out.
  • Bathrooms and bedrooms are very likely to have mirrors.
  • Vanity cases.
  • Still pools of water.
  • CDs and DVDs are highly reflective.