1. Administrative Next week (April 7 th in class) the Design Analysis Project is due (this is required for all students and it is 15% of the final grade). If you have not done so, start working on it now. We grade this project rigorously; particularly the level of effort put into the work. We expect that you will go the "extra mile" for this project and put a lot of effort into it. Next week (April 4 th in class) is Test # 2. Covers all of Unit 2.

2. Games as Cybernetic Systems (Ch. 18)

3. Cybernetics Resulted from Information Theory (Ch. 16) and Information Systems Theory (Ch. 17) Focus on how dynamic systems change over time Cybernetics is used to study organizations –Large companies –Governments Basic principle: output-feedback- adjustment

4. Elements of a Cybernetic System “The feedback Loop” Environment Comparator Sensor Activator AC-unit-in-a-room example feedbackadjustment output

5. Kinds of Feedback Example of each for the AC-unit-in-a-room example  Negative: temperature(room) > 75  then activate cooler  Positive: temperature(room) > 75  then activate heater

6. Simple Cybernetic Design Lets combine two feedback loops that maintains the temperature in a room stays between 65  and 75  –We have a cooler and –We have a heater Lets do one that maintains the temperature in a room at 70 . Same conditions as before

7. Example of “this stuff” in games? Positive/negative feedback in games? –An example of positive feedbackpositive –An example of negative feedbacknegative

8. Feedback Loops in Games ( Marc LeBlanc) Environment Comparator Sensor Activator feedbackadjustment output Game state Game mechanical bias Scoring function Game Controller Game state  Information known to all players  Information known to only one player  Information known to the game only  Randomly generated information

9. Example of negative Feedback: Downforce http://www.youtube.com/watch?v=37g5uNwmqz4 http://www.youtube.com/watch?v=z-OQzqUdbs4 Negative:  Simulated gravity vs. player  AI lets itself catch-up if you are loosing  AI catches up if you are winning

10. AI lets itself catch-up if you are loosing feedback adjustment output Game state Game mechanical bias Scoring function Game Controller Position of autos Configuration of track … Player loosing? Formally: Distance(player, finish) > Distance(leadingCar, finish) Player position, leadingCar position Formally: Distance(player,finish), Distance(leadingCar,finish) Slow down leading-car Formally: speed(leadingCar)  speed(player)  f(Distance(player, leadingCar)

11. Simulated gravity vs player control feedback adjustment output Game state Game mechanical bias Scoring function Controller Position of autos Configuration of track speed… Player going out of road? Player direction Road direction Steer car towards road

12. Mortal Combat: combo feedback adjustment output Game state Game mechanical bias Scoring function Controller Health Points player Health points opponent Disabled (Yes, No) Opponent situation (chance for next combo, no chance) Disabled = Yes Opponent situation = chance for next combo Disabled, Opponent situation Disabling attack

13. Difficulty Levels Brigette Swan Adaptation to the quirks and habits of a particular player over time. Many games implement difficulty sliders. Common: –start early levels easy –More difficult as game progresses –Difficulty can be amount of information available! –Dynamic Difficulty Adjustment (DDA)

14. Dynamic Difficulty Adjustment (DDA) -- The Oblivion Controversy Idea: adjust game so that it remains challenging (negative feedback) It is an RPG game like say Diablo but… As your avatar levels so do all mobs in the game –So for example you “clean” a dungeon at level 1 killing some rats, at level 10 those rats will be armored and will hit much harder Does it still have meaningful play as a result?

15. Use of Feedback in Games ( Marc LeBlanc) Stability: –Negative feedback stabilizes a game –Positive feedback destabilizes a game Game duration –Negative feedback can prolong a game –Positive feedback can end it Success: –Positive feedback magnifies early success –Negative feedback magnifies late ones Control: –Feedback systems can emerge from games –Feedback systems can take control away from gamers  … and result in lost of meaningful play! Examples?