Wands store spells and release them through the use
of the zapping skill.  Wands can only be dropped in
power rooms, which can be found in some guilds and
in player-owned castles (HELP SPELL MASONRY). 

  While any number of wands can be carried, zapping 
becomes impossible if the user holds more than two,
due to the instability of the magic contained within
them.

See also: help skill zapping, help wandsnap