I'm not sure if this is already in PRF or not, but I'd like to see a liar type NCP that lies to players. Perhaps more than one kind of liar.
I.E., a character hanging around the gates of a city that approaches a player, offering information to lead you to a fine inn. And instead leads you into an ambush in a dark alley.
Or, offers to lead you to a hidden area where you may find treasure: and leads you to a manhole. When you enter it, you drop into a catacomb/sewer that requires a good deal of work to get out of it. There could be treasure, but you will work to earn it.
I think AI should only be used for non combat situations . For PVE fights it is an overkill as has been noted above .
Implementing Utility theory AI would be amazing. It's not too resource intensive, and best of all you don't paint yourself into a corner dealing with edge cases like you can with behaviour trees and state machines. This would allow VR to design enemies and encounters that use a wider range of abilities and in a more intelligent/interesting manner, than has ever been seen in a MMORPG. Utility AI is not some pie in the skynet fantasy it is well understood and is being used in some games already. Utility AI can be used outside of combat as well of course, it could be used to determine what NPC's do throughout the day, or even what quests they offer players. Utility curves can also be weighted by faction, 'mood' or anything else the designer decides. The possibilities for Utility AI in Pantheon are very exciting in my opinion!
As a quick example, Utility AI would allow a situation where an NPC that was snared and bieng kited, would choose to seek cover and break line of sight, instead of mindless chasing the player to thier death. Or a townperson who normally gives rewards for gnoll teeth but is really hungry and would really prefer some food and drink before they accept any more gnoll teeth. Utility AI is incredibly flexible and can be used for any type of NPC decision making you can come up with. Everything from what abilities to use to which direction to move.
Utility AI is not something that is easily summarized so I've linked a video that goes over it.
https://www.youtube.com/watch?v=jse_ZleruJU
Alot of the examples that people have posted to this thread would be covered by Utility AI
Code Name: Rumormonger
Mechanics: A NPC that can have its speech patterns and quest hints modified by players. Either by paying a guard to spread false rumors or getting him drunk and feeding him fish tales the guard will occasionally spot false information encouraged by players. A high enough perception will alert you if the information is false.
Nod to Nephele and Caine for making me think of this
To borrow from Trasak's convention:
Code Name: Wannabe
Mechanics: An NPC who is trying to make a name for itself. In an effort to impress, the Wannabe will take on the characteristics of a nearby mob in order to outdo the others and appear greater than it is.
Code Name: My Favorite Customer!
Mechanics: An NPC vendor who receives a certain quantity and/or quality of goods, and (through perception) offers quests for specific items or goods with unique rewards (cosmetic (maybe merchant's outfit), functional (membership to merchant's guild, offering small discounts), rare recipes, etc.)