Games where emotions are used in the game mechanics

In the summer of 2012 I started to compile a list of games where emotion, affect or appraisal is used as part of the game mechanics. After having made a small list, I asked friends via social networks and via the mailing list for Project Horseshoe to come up with more suggestions. 

Here are the games that were suggested, in no particular order:

Psychonauts

Ico (the 'feeling' between the two main characters)

World of Warcraft (ex: the fear spell that characters with warlock abilities can cast)

Facade

Prom Week

Black & White

The Sims, The Sims 2, The Sims 3

Diner Dash
(Nicole writes: "Diner Dash is my favorite example of progress / feedback on NPC faces. Managing the emotions seen on customers' faces IS the core mechanic. Serve them quickly they get happy, ignore them they get angry and steal money from your tip jar.")

King Arthur: Pendragon
 (Ken Rolston directing towards an URL: "Here's an example of play when a player knight first encounters Queen
Guenever: http://www.gspendragon.com/adore.html")

The Act
(Gamasutra: "The game, which was meant to release in the mid-2000s, hoped to create an emotional link between player and character through detailed Disney-style hand-drawn animation, with a simple control interface -- users simply turned a dial to make the main character more forceful and confident, or more tentative and passive, depending on the situation." http://gamasutra.com/view/news/172928/Handdrawn_iOS_interactive_comedy_began_as_a_failed_arcade_experiment.php#.UGR2241y684)

Ars Magica,
(Giles Schildt:  I have vague memories of attributes like "presence" driving some kind of emotional character interaction mechanics, rather than just merchant prices and spell availability like the more-or-less equivalent "charisma" did in then contemporaneous versions of D&D.)

Deus Ex
(Kyle Brink: "There's a tidbit in Deus Ex: Human Revolution where, with the right tech upgrades, you get to gradually understand an NPC's personality (alpha, beta, or omega) via ephemeral cues given over the course of a conversation. Once you've gotten enough cues, you have the option to attempt to influence the NPC by releasing pheromones appropriate to what personality type you think they are.
Not strictly emotional, but definitely non-verbal and based on getting to know the other person's mind a little."

John Carpenter's The Thing
(
Evan Skolnick: J"ohn Carpenter's The Thing  for PlayStation 2 had a really cool "trust" system in which squadmates' trust of your playable character was constantly measured and updated based on your actions... if their trust in you got too low, they would accuse you of being an alien and start firing on you.)

 X-Com games
(Evan Skolnick: "the original X-Com games kept track of squaddies' morale and those with low bravery could panic in the middle of a fight that wasn't going well, dropping their weapons and gear and running for cover (essentially becoming temporarily useless to you). Or worse, going completely nuts and firing in random directions. :-))

Civilization / Alpha Centauri
Squirrel Eiserloh: "In Civilization / Alpha Centauri, your citizenry has a level of anger/unrest
which must be managed as a mechanic and which, left unchecked, will have
gameplay ramifications (i.e. workers revolt / drone riots)."


Roller Coaster Tycoon
Squirrel Eiserloh: "Games like Roller Coaster Tycoon also use emotions as mechanics in a way
somewhat similar to The Sims."

Ultima IV
Squirrel Eiserloh "Lastly, while it's even less literally what you mean perhaps, I find Ultima IV to be one of the best, most interesting integrations of "character traits as mechanics" in a game that I've ever seen.  In this case it's more of "what do you think of yourself" and "what does the universe think of you" 0sort of thing, but it is certainly central not only to the game's theme, story, and world but is an active part of the game's core mechanics."

...continue with Link

Rule systems: 
GURPS (Giles Schildt:  "GURPS has a fairly complex reaction roll system, with modifiers for behavior, appearance, reputation, etc. Players can choose coercive methods (e.g. Intimidate or Sex Appeal) or diplomatic methods to make friends and influence NPCs. There are also rules for dependents which focus far more on the emotional relationships than the legal ones.")

 D&D (Giles Schildt: newer editions have some charisma based skills for influencing others' decisions by manipulating their emotions, for example intimidation through non-magical fear)

White Wolf's Vampire system (Giles: "has mechanics for various emotional reactions and loyalties, and a wider than typical range of "emotional" stats like Empathy, Manipulation, and Self-control; as you might infer from that last stat, there are rules for situations where a /character/ might have an emotional reaction and do things his /player/ doesn't want him to. Another example of a mechanic central to some games is "blood bound," which the rules describe as an induced feeling of "love" for the "regent.")

Suggested general features:
"Any berserker rage implementation." (stephane)
 "Fear as a catalyst for insanity is a pretty central mechanic across the horror genre. Some notable examples, Eternal Darkness on the N64, and Arkham Horror or Haunting at the House on the Hill for board games. It's typically represented by some form of "sanity meter" that functions just like a health bar for psychological damage." (Jake Forbes)


Factions' traditional feelings about each other in general fantasy-RPG mythos
Squirrel Eiserloh: ("MMOs and RPGs have been mentioned here but I didn't notice if anyone specifically called out faction as one of their chief in-game emotion
mechanics.  Dwarves hate giants; elves hate you (for now - until they like you later, because you did them favors); lizardfolk hate you less because you have been killing a lot of their sworn enemies, the skaven rat-men. Mechanical effects reflect in NPC dialogue, trade prices, safety ("kill on
sight" vs. "tolerate" vs. "we will actively protect you"), etc.  Certainly in D&D and similar games every dungeon master has been using emotional
mechanics and factional disposition of NPCs towards players since the dawn
of time (no offense intended to those who predate the dawn of time... Ken).")


Thanks to all who contributed with any of the game suggestions above (in no particular order):
Keyvan Acosta, Katherine Isbister, Nicole Lazzaro, Ken Rolston, Stephane Bura, Giles Schildt, Kyle Brink, Jake Forbes, Evan Skolnick, Squirrel Eiserloh




Sources for more information:
Katherine Isbister's talk at GDC'08 contains good tips on what traits players appreciate in player characters and non-player characters respectively.