Format: 
cast 'detect magic'                     cost: 5 mana
cast 'detect magic' <target>            cost: 5 mana

The detect magic spell is one of the lowest level mage spells, and one of
the easiest to learn to cast.  This is not a duration spell - instead it
gives the caster a 'snapshot' of the magical aura of the target.  The
relative strengths of various spells being used by the target determine
the aura of the target.

There are several instances where this spell may give inaccurate or useless
information about the target.  Certain spells can radiate very powerfully
into the targets' aura.  Often the presence of powerful spells (most notably
the cleric spell sanctuary) can totally eliminate traces of other spells
on the target.  Detect magic is also not effective on highly magical
creatures.  Yes, it will detect magic, but without more precise knowledge,
little can be gained from it.

Those targets that make no effort to conceal thier magical auras and have a
great many spells at work at once will show the brightest auras with this
spell.  At higher casting levels, even a single simple utility spell can be
detected on the target.

Detect magic can also be cast without a target, in an attempt to discern
parts of the mana field in the area.  This can be dangerous, however, as
rooms with extreme amounts of mana may overload the senses.