Semi-Autonomous Avatars in World of Minds A Case Study of AI-based Game Design

1. Semi-Autonomous Avatars in World of MindsA Case Study of AI-based Game Design ACE 2008 Yokohama, Japan Thursday, Dec 4, D1, 9.00 Mirjam PalosaariEladhari Gotland University, Sweden Michael Mateas University of California, Santa Cruz, USA

2. Introduction Någonting om mig – doktorand på hgo (via teeside, CS + mathematics), tidigare spelprogrammerare, bg även littvet&beteendevetenskap. Detta, exempel på ai driven spel design forskning EIS labbet i University of California SC. (MM) - handuppräckning: mud. Ultima online. EQ. WoW? CRPGs? TTRPGs?

3. Characters in MMOs • Majority of characters in MMORPGs are playercharacters/avatars. • Mostcharacter interaction takeplacebetweenavatars. • NPC’s in MMORPGsmainlygivequests, sellitems or give information about the world.

4. Round and Flat • A flat character consist of only a few traits and usually have a single, static aim, transparent to the audience. • A round characteris complex and capable of contradiction, surprise and change. Round characters have a multitude of contradictory traits. (Forster, Aspects of the Novel, 1927)

5. Chatman on Round Characters “Round characters […] possess a variety of traits, some of them conflicting or even contradictory [...] We remember them as real people. They seem strangely familiar. Like real-life friends and enemies it is hard to describe what they are exactly like. “(Chatman,Story and Discourse, 1978) In MMORPGs, the player characters ARE real

6. Round and Flat • A flat character consist of only a few traits and usually have a single, static aim, transparent to the audience. • A round characteris complex and capable of contradiction, surprise and change. Round characters have a multitude of contradictory traits. (Forster, Aspects of the Novel, 1927) NPCs Avatars

7. WhereMMO’sfail Despite the focus on player-to-player interaction, current MMORPG designs fail to provide explicit support for helping players to roleplay and fail to incorporate such social interaction and roleplay into the game mechanics themselves.

8. Goal • To develop an AI-based game mechanic that brings round characters into MMORPGs to support the player in roleplaying through their avatar. • Find ways to utilize the richness of the present human intelligence in virtual game worlds and via, the right triggers, enrich the game experience in terms of characterdriven drama woven into the virtual world through its rulesystem.

9. Outline and summary One of the most exciting possibilities in game AI research is for AI to open up new game design possibilities. New AI will suggest new design possibilities while design will push back on AI requirements. This paper provides: • A concrete case study of AI-centric game design, specifically describing how AI can be powerfully and effectively used in an MMORPG design. • The Mind Module, a technical framework for modeling personality and emotion for both player and non-player characters. • The World of Minds (WoM), an MMORPG that employs an AI-based game mechanic designed around the MM. • Lessons learned from a paper prototype playtest of the mechanic.

10. Mind Module overview

11. Mind Module (MM) Overview • a semi-autonomous agent architecture • built to be used in a multiplayer environment as a part of the player's avatar. • The MM models the avatar's personality as a collection of traits inspired by the FFM • maintains dynamic emotion state as a function of interactions with objects in the environment and trait values, and summarizes the avatar's current emotional state as an inner and outer mood • Spreading Activation Network (SAN)

12. Deconstruction and reconstruction • In psychlogy and neuropsychology the complexity of the human mind is made morecomprehensible by deconstructioninto subsystems. • As builders of virtual humans weneed to reconstruct agents that canfunction in way that is believable and useful to the users in the contexts and systems wedevise.

13. Nodetypes Weighted network of interconnected nodes

14. Two-dimensionalaffect plane • Emotions: brief and focused (ie. directed at an intentional object) disposition • Sentiments: permanent and focused disposition • Mood: brief and global disposition • Personality: permanent and global disposition

15. Personality • Plethora of personalitytheories; psychoanalytic, behaviorist, cognitive and biophysiologicaltheories. • Traittheorypioneered by Allport (1930ies) where the most prominent personalityassessment is called the FiveFactorModel. • (alsoused by Guoliang, Klesen, Khirsagar, El Jed, etc)

16. FiveFactorModel NEO PI-R (alsocalled OCEAN)

17. Personality Trait Nodes Defines how you ”are”. Traits: OCEAN model (Big five)

18. Emotions in MM 13 ”basic emotions”, common to primates, as described by Ekman, Tomkins, Nathansson

19. Emotion Nodes Define how you feel right now 13

20. Mood In everyday sense: An overall state or quality of feeling at a particular time Changes slowerthan emotionsTemporaryHighlycontextual Lingers evenif the contextchanges Becomes part of the nextcontext Individual – ”same” type of eventresult in differents moods for different people.

21. extroverted side of the mood, how the character emotionally is relating to the game world and to other characters. Moods private, inner mood

22. Inner and OuterMood • The inner mood is the private sense of harmony that can be present even if the character is in an environment where events lead to a parallel mood of annoyance. • The nature of the outer mood is social, and as such tied to emotions that are typically not only directed towards another entity but also often expressed toward an entity, such as anger or amusement. • The two scales for the mood nodes open up the possibility of more complex states of mind than a single binary axis of moods that cancel each other out.

23. Mood Define how you feel today

24. We interpret the moods of peoplearoundus, and choosehow to actaccordingly

25. Sentiments – Emotional attachements • MM allows several sentiments ie, of different emotions, to be attached toward an other entity, thus creating a compound set of sentiment. • emergent sentiments origin from interactions with other entities in the world, thus creating emotional memories. • authored sentiment sets have certain pre-set combinations. For example ``infatuation" is a combination of interest/excitement/amusement and joy toward another character.

26. Player might realize it is a good idea to RUN!

28. Sentiment An emotional disposition towards a specific object or class of objects. Define how you generally feel about specific things

29. Nodetypes Weighted network of interconnected nodes

30. MM Summary • The MM thus provides the player with information about the avatars feelings toward other entities in the world. • Proximity to objects or characters affect the emotions, and thus the mood of an avatar, functioning as information the player can use to form an agenda for game play.

31. World of Minds Game Play

32. World of Minds Summary • Prototype mutiplayer game world where the personalities of the inhabitants are the base for the game mechanics. • When interacting with other characters, the action potential depend upon the player character's current mood and personality

33. Basic Game Play of WoM Players need to defeat physical manifestations of negative mental states by using - Spells - Affective actions The spells available to the character depends on personality The affective actions available to the character depends on the current mood.

34. Spells and mind energy • Spellscost Mind Energy to use (”mana”) • Attacks reduce Mind Resistanse (”health”) • The amount of Mind Energy is tied to OuterMood • The amount of Mind Resistanse is tied to Inner Mood

35. Fluctuations of Energy and Resistanse

37. Affectiveactions and Mood • players can affect each other's moods by using affective actions (AAs). • AAs are actively chosen by the players • the AA ``Comfort" can be used successfully on targets that have an active emotion node of Sadness, but only if the player's own avatar is not in the area of Furious on the mood matrix. • If the AA Comfort is used successfully the values of the emotion nodes Sadness and Anguish of the target are diminished, which in turn affects the mood of the character.

38. Mood manipulation • Currentmoodaffects: • Regeneration of Energy and Mana • The range of availiablecurrentactions Thus, by affecting the mood of a anothercharacterthe action potential of that character is changed.

39. Mood, Spells and Resistanse

40. How a sentiment and/or a manifestaion is born in WoM

42. Playtest

43. Playtest Research Questions The playtest was designed to elicit design feedback from players on three different questions: 1) During gameplay, are players able to "reverse engineer" the MM to build a mental model of how to manipulate emotional state to achieve gameplay goals? (For any successful game design, players must be able to build a model of the mechanics that allow them to successfully interact with the game.) 2) Understand the player's theory of how traits relate to MM state and gameplay in order to gather new design ideas for how traits might influence emotional state and gameplay. 3) How do the players perceive the relationship between the emotional state maintained by the MM and the game mechanics and interaction options that depend on that state?

44. Approach Evaluation of the game design via a paper prototype During the play tests, the test leader walks individual players through a paper simulation of several scenarios. Players are asked to think aloud while playing the game; additionally, the test leader stops the game at several points and conducts interviews. (User-Centered Design, where the user's experience is a main driver for design, Rapid prototype and playtesting)

45. Ten players individually went through five game mastered scenarios where her avatar had a mind, represented by the character sheet.

48. For each playtest, the participant: • Filled in a short (less than ten questions) survey on demographic data and previous gaming experience. • Took the IPIP-NEO Personality test and emailed the results to the test leader. • Filled in a short survey about their experience taking the personality test and their opinions about the use of personality traits for avatar creation. • Participated in the playtest, which took between 1 and 1.5 hours. Each playtest session consisted of playing five scenarios, and answering questions in two interviews, one in the middle, and one at the end of the playtest. Each session was videotaped. • Filled in two more short surveys, one focused on sentiment objects, and the other on general impressions of the experience.

49. Playtest • During the five scenarios, the player was guided through using the main categories of actions in the game including : • affective actions • navigation in a landscape of sentiment objects • mind magic spells. • Using the character sheet the test leader updated the state of mind of the avatar and NPCs, showing the player the effect of her actions in the game in terms of fluctuations in emotions, mood, mind energy and mind resistance. • In order to best capture player's problem-solving processes within the game, and to best understand potential areas for confusion, the players were given minimal explanations about how and what to do. • At any point, players could access a ``help system" in order to ask any question. • The twenty-two interview questions focused on the player's understanding of the relationship between values in the MM, effects of game actions, relationship between personality and availability of actions such as spells, etc