Some catagories of dreams could include:
Euphoric Dream State - Pure bliss. *WINK* *WINK*

You are entirely detatched from the real world, and this state of sleep heals FAR better then any other.
Physically Detatched Dream State - Your body is disconnected from your dream; if you get damaged you will wake up without damage.
Physical Dream State - Your body is
connected to your dream; if you get damaged you will wake up with slight damage. This is never lethal though. More of a \"Hey, when did I get this scar?\"
Nightmare Dream State - You dream body is FULLY attached to your physical body, any and ALL damage will be created on your physical body. There is, however, a good chance to \"snap out of it\" before you are slain by enemies. The maps are also heavilly depressing; you don\'t heal or heal very little while in this dream.
Nightmare-Induced Dream State - Only cast by a magic spell or poison, this locks you into a Nightmare dream state with no way out. You do not heal, and possibly even lose health while dreaming this sort dream! You can only be awaken by:
1) Death.
2) Allies, come to free you by entering your dream; Destroying the \"sign\" in your dream (The \"Sign\" can be anything; a tree, a glowing sword, even a innocent-looking little NPC child. It IS a nightmare, after all; you MUST do things you wish not to do normally.)
3) Killing or Disabling the object, person, or persons responsible for causing the effect
4) Given enough time, you will eventually wake up. However, one type of dream state cannot be escaped from so easilly... 8o
Nightmare-induced dreams take place in the location of the inducer\'s choice such as: a battle feild (possibly battle still raging!) a abandoned city, a diseased hamlet, a charred and dead forest, as well as several other nightmare-ish/hellish areas.