Alter Aeon Online Help

Keywords are:  'mage spell detect magic aura halo'

Spell: detect magic             Mana:   5  Int: 17  Wis: 13  Lvl  9 Mage  (42%)
                                (helpful)   Requires: spell lore
                                Group: Mage basic magics

Usage:
cast detect magic <target>
cast detect magic room

The 'detect magic' spell is very easy to learn to cast.  This is not a duration
spell - instead it gives the caster a glimpse of magic active on and around
the target. Different types of spells will appear as overlapping auras of
various colors. The color indicates the type of spell being detected. For
instance, a fire spell like burning hands will add an orange hue, while the
force shield spell will manifest as a cyan halo.

Casting detect magic on a target allows casters to more effectively remove
spells with 'dispel magic'. As dispelling alters the magical aura of the target,
detect magic works best alternating between casting it and dispel magic.

There are several instances where this spell may give inaccurate or useless
information about the target. Powerful cleric spells can mask other portions
the target's aura, sanctuary in particular. Likewise, elementals and highly
magical creatures radiate powerful magic that overwhelms the aura of any
spells that may be cast on them. Cleric curses and magical hexes have
relatively weak auras and are better detected by the 'reveal curse' spell.
The mage 'mana shield' spell blurs the target's auras and makes discerning
the relative strength of the spells impossible

Detect magic can also be cast on the place you're standing, and will show
you if there are any wards or spells anchored to the area.  It can also
show the flow of magic from one place to another.