Something I've ALWAYS wondered about in AD&D (and now C&C) is Fear - and not magical or monster induced fear either, the natural fears people carry within themselves.
Its not just making the save, its WHEN its appropriate to ask the Players to make them.
For Example -
Tobo is a 1st Level Thief, he's never been on an Adventure - he's really REALLY green. His first encounter upon entering a Dungeon is a Giant Spider. He's never seen anything beyond a common garden spider before.
I (as a DM) would rule that Tobo would HAVE to take a Fear Save, or have some adverse reaction to encountering the disturbing creature.
Yet the rules as they stand, do not accommodate 'newbies' encountering things which they might find frightening. Plus, Giant Spiders (even the REALLY huge ones) and Phase Spiders DON'T cause Fear! Even a Drider doesn't cause fear. If I saw a Dark-Elven Spider Centaur FOR REAL I would most likely cack my pants Lol, even desensitized to scary things as I am personally (and the world is in general).
My 'take' on the matter is that when a new Character (3rd Level or lower) encounters something potentially frightening they should make a Fear save. Should they pass, there is no further problems. Should they fail, the very next time they encounter such a creature (even if they are over 3rd Level) they make another Save vs Fear, this time with a difficulty of 2. Should they pass, as before there will be no further problems. Should they Fail this time, the Character has developed a minor phobia about such creatures and will have to make a save vs. Fear each and every time they encounter one in the future. Obviously Magic can circumvent such things.
Now this idea has to be tempered with some common sense, for example - its no good making your Wizard or Cleric taking a Fear test vs Skeletons, as they would have been made aware of such creatures during their training. Its also not a good idea making a Ranger or Druid make a save vs. a giant animal - because even though its size is exaggerated its still an animal and well within a Ranger or Druids experience to deal with.