1. THE RATIONALITY ENGINE Homo Economicus vs. Homo Ludens Jonas Heide Smith (smith@itu.dk) ITU, 13/5-2005

2. THE RATIONALITY ENGINE The game-gaming gap Game Player

3. THE RATIONALITY ENGINE What are players like? The common assumption: They are über-selfish utility maximizers True? no. true? Yes. Compulsory footnote: ”Selfishness” is a tricky term.

4. THE RATIONALITY ENGINE

5. My suggestions: It’s better to be wrong than unclear (successful strategy in media studies and economics) Clarify assumptions and then analyze, analyze, analyze Test predictions on real players

6. THE RATIONALITY ENGINE Analysis Guiding questions: –What will the players do? –What will be the result of aggregate player behavior? Technique: –Keep It Simple, Scholar Be as general as you can reasonably be –Describe victory conditions (that which the player is meant to maximize)

7. THE RATIONALITY ENGINE Example: Spacewar Objective: Win by destroying the opposition Sum-type: Zero-sum –Cooperation: None –Communication: None Player 2 CooperateDefect Player 1 CooperateBad, BadBad, Good DefectGood, BadOK, OK

8. THE RATIONALITY ENGINE Example: Fire Truck Objective: Win by collectively steering truck Sum-type: Zero-sum (players vs. environment) –Cooperation: Full –Communication: Coordination Player 2 CooperateDefect Player 1 CooperateGood, GoodBad, Bad DefectBad, Bad

9. THE RATIONALITY ENGINE Example: Joust Objective: Score points by killing others Sum-type: Non-zero-sum –Cooperation: Unstable –Communication: Coordination, promises Player 2 CooperateDefect Player 1 CooperateGood, GoodBad, Great DefectGreat, BadMediocre, Mediocre

10. THE RATIONALITY ENGINE Example: Gauntlet Objective: Score points by killing others Sum-type: Non-zero-sum –Cooperation: None (?) –Communication: Coordination, promises Player 2 CooperateDefect Player 1 Cooperate2,20,3 Defect3,01,1

11. THE RATIONALITY ENGINE TypePlayer interestsChallengeSum typeExamples CooperativeExactly alignedGame environment or other team AnyFire Truck (1978), co-op mode in Halo (2001) Semi- cooperative Collective goal shared but individual goals differ somewhat. Game environment or other team and to a lesser extent the allied player(s. Non-zero- sum game with allies, any type against game environment or other team Joust (1982), Gauntlet (1985) CompetitiveDirectly opposed. Competitive two-player games will never inspire in-game cooperative behavior while games with more players may inspire temporary coalitions between players. The other player(s) Zero-sumPong (1972), Tekken 4 (2002)

12. THE RATIONALITY ENGINE What can YOU do? Help analyze –Pay particular attention to mixed-motive games (like Counter- Strike) –What to do with MMORPGs? Test it –Run tests –Help analyze data Let’s get that Nobel prize