Games as Cybernetic Systems (Ch. 18)

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

Elements of a Cybernetic System“The feedback Loop”

Environment

Comparator

Sensor

Activator

• AC-unit-in-a-room example

feedback

adjustmentoutput

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 cooler

Simple Cybernetic Design

• Lets combine two feedback loops that maintains the temperature in a room stays between 65 and 75– We have a cool air maker and – We have a heat air maker

• Lets do one that that maintains the temperature in a room at 70. Same conditions as before

Example of “this stuff” in games?

• Positive/negative feedback in games?

Feedback Lops in Games(Marc LeBlanc)

Environment

Comparator

Sensor

Activator

feedback

adjustmentoutput

Game state

Game mechanical bias

Scoring function

Controller

Game state

Information known to all playersInformation known to only one playerInformation known to the game onlyRandomly generated information

Example of negative Feedback: Downforce

http://www.youtube.com/watch?v=37g5uNwmqz4 http://www.youtube.com/watch?v=z-OQzqUdbs4

•Negative:Simulated gravity vs. playerAI lets itself catch-up if you are loosingAI catches up if you are winning

AI lets itself catch-up if you are loosing

feedback

adjustmentoutput

Game state

Game mechanical bias

Scoring function

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)

Example Positive Feedback

http://www.youtube.com/watch?v=bEGTX1cLeMo

Homework: Next Class

• Construct feedback loops (see Slide 9) for:– Simulated gravity vs player control (Slide 8)– Mortal combat (Slide 10)

• Make sure to clearly identify four elements in detail

Simulated gravity vs player control

feedback

adjustmentoutput

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

Mortal Combat: combo

feedback

adjustmentoutput

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

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)

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?

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?

Test # 2

• Chapter 11 to Chapter 18 – Class + Book

• 6 student presentations– Instructional Games + S.L.V