1.) Mentality Bar
Roughly based off a combination of the "insanity" idea from gamecube game "Eternal Darkness: Sanity's Requiem" (which, by the way, is an awesome game ) and an idea I had for an MMO once. More off the second one, since I want to be original.
Basically, my idea was that certain attacks and spells, in addition to coming in contact with certain enemies, would reduce one's "Mentality bar," which functions sort of like hit points. It would also function as the "sleep meter," if I decide to put a sleep feature into the map. Higher MB means that your spells are stronger, and represents the character as being alert. If your MB gets dangerously low, you may find that your character's movement is slowed. When you run out of MB, you pass out and are vulnerable to mind control and possession spells (this is how players with a mind control abilities can temporarily take other players).
While mind controlled, a copy of the player fights a monster in a separate area that represents their mind (in the event of mass mind control, the controlled fight together). If the player dies in this area, he simply respawns. You cannot lose to this monster, as you keep trying until you kill it. Once you kill it, you regain control of your body and wake up wherever your body is at the current time (this may very well be in a dungeon or a dark alley or something).
If possible to implement (which I highly doubt), hallucinations that only the player in question can see may appear when MB is low (similar to how the character in the gamecube game I mentioned earlier will start seeing things as their sanity gets lower).
2.) Time and Technology
I was thinking that not only should I represent day and night in my game, but also the progression of technology as computer characters make new breakthroughs. As the player advances through the game, new units and abilities will start to show up, and often manifest themselves as bosses at first (for example, the first tank is a boss in the Secret Volano Laboratory). If possible, I will try to get comps to upgrade as the game progresses also, to represent the progression between, say, longbows -> rifles and swords -> magically powered light sabers or something.
In general, as technology progresses, the gnomish/human New Order will advance, as the Grand Old Regime led by the Undead declines. (Hmm, I should probably come up with better names. "New Order" sounds like "New World Order," and "Grand Old Regime" sounds like "Grand Old Party." People might think that it's a metaphor about the GOP fighting the New World Order, when in reality, the GOP would do nothing so noble if there really was a NWO. Any ideas for better names?)
3.) Newspapers
To announce new breakthroughs and inform players of new quests they could take, a daily newspaper will be available. Headlines might read "New breakthrough rumored to have been tested in the Underworld!" or "High Director loses his glasses," or "Big Scary Thing threatens small village," for example. The player can keep a few newspapers at a time, although generally, after a few days, the newspaper quest disappears (I mean seriously, did you really think that small village would wait 10 days for you to save them from the Big Scary Thing?).
4.) Reading
The idea is that you go into a library or find a book somewhere... and read stuff. This is good for three things (at least):
a.) Getting fun background information that may be useful later. You may also find stuff about areas you could go to (for example, you may want to read up on the Ancient Vampire Crypt before entering; the book may have information that could save you time, like "The crypt is rumored to be littered with gold-colored booby traps" or "Vampires heal their wounds as the moon rises."). Of course, you could just bulldoze your way through, but knowledge might make it easier.
b.) Learning new spells. Instead of just receiving a message that says "You found a magic tome! You got a new spell!" or something like that, you actualy have to READ the dang tome and in doing so, simultaneously learn the spell in-game and learn how to cast it.
c.) You can take the path of the scholar instead of the warrior, gaining experience through knowledge instead of warfare. Obviously, this wouldn't work very well for strength-based purposes, but it would be feasible to gain fighting prowess by reading a nice book on ancient martial arts.
5.) Talking
It appears that someone else has come up with this same idea (I forget who, but I saw it on SEN). I thought of it independently before they did. To be fair, though, I was inspired by one of the Old SEN tutorial articles I read that were linked to on Falkoner's site.
Anyways, the idea is that, for example, instead of just bowing to the king and saying "Yes, master, I will find your glasses for you" (or whatever the quest may be), you have the option to ask him questions and disobey him. Besides saying "Yes master..." you could also have an option to say "Wait, how can you see who I am if you need the glasses to see?" or "Quick, my followers, the King is incapacitated! Storm the throne!" (Obviously, the third choice would have negative consquences... unless you actually DID have a coup prepared... )
In general, asking questions will get you funny background information, although occassionally certain remarks may provoke an attack (for example, you could say "Uh, hey King, I was reading the geneaology records, and I couldn't find anything about your father..." or "What was that shadowy figure I saw as I entered your palace?" and he could respond "Oh crud, he's on to me... GUARDS, KILL HIM!"). Reading books may also open new conversation paths, as the geneaology records did in that particular example.
Hmm, I thought I had more than this. I probably forgot something, or decided it wasn't important. Oh wells. What do you guys think? Workable stuff?
None.