Format: 
cast 'infravision' <target>             cost: 12 mana
cast 'sense life'                       cost: 12 mana
cast 'detect evil'                      cost: 12 mana
cast 'detect invisibility'              cost: 12 mana

The above spells are all detection spells. Sense life allows you to "feel"
a presence in a room. It has the potential to detect hiding or invisible 
mobs, and can sense them in the dark.  On the other hand, sense life does not
tell you anything about the creature, only that a life form is present.
Infravision is a spell that allows you to see in the dark. It reveals all
the "living creatures" in a room, but does not illuminate the room.
Detect evil shows different color auras around all evil entities encountered. 
Detect invisibility will allow you to see invisible items and entities.