Games as Cybernetic Systems systems theory + information theory thinking about feedback

COSC 4126 cybernetics Cybernetics - wikipedia  Cybernetics is a theory of the communication and control of regulatory feedback.  The term cybernetics stems from the Greek Κυβερνήτης (meaning steersman, governor, pilot, or rudder).  Cybernetics is the discipline that studies communication and control in living beings and in the machines built by humans.

COSC 4126 cybernetics Homeostasis Homeostasis is the property of an open system to regulate its internal environment to maintain a stable condition, not rigidly fixed but maintained within a bounded acceptable range. e.g., eating, drinking, breathing enough to sustain life - simulated in characters in many games - Sim games are based on homeostatic models

COSC 4126 cybernetics Feedback loop  an activator produces an effect  feedback allows the effect to influence future action activator acts to produce effect/result result sensorcomparator activates or not goal external effect

COSC 4126 cybernetics cold outside Feedback for homeostatis  Negative feedback: how a system reacts to maintain stable condition furnace generate heat temperature of room thermometerthermostat activates or not temperature setting

COSC 4126 cybernetics Temperature control time goal temperature actual temperature furnace operating

COSC 4126 cybernetics Negative feedback - stability  The term cybernetics stems from the Greek Κυβερνήτης (meaning steersman, governor, pilot, or rudder). maintains course close to desired direction  other examples funnel, sloped wings of aircraft predator / prey ecologies driving a car

COSC 4126 cybernetics Automation and high level control activator acts to produce effect/result result sensorcomparator activates or not goal higher level (containing system) set goal

COSC 4126 cybernetics Automated control by goal setting  e.g., thermostat plus air-conditioner and furnace high level control – set goal temperature thermostat activates furnace and air- conditioner as required to keep temperature in range reacts to external heat and cold

COSC 4126 cybernetics Negative and positive feedback  negative feedback modulates an action  positive feedback catalyzes an action

COSC 4126 cybernetics LeBlanc,1999:  Negative feedback basketball for every N points of difference in the score, the losing team can put another player on the court  Positive feedback basketball for every N points of difference in the score, the winning teams can put another player on the court

COSC 4126 cybernetics Positive feedback  amplifies effect of action  threatens a homeostatic system activator acts to produce effect/result result sensorcomparator activates or not goal opposite condition produces positive feedback

COSC 4126 cybernetics Positive feedback  e.g., climate change in Arctic atmospheric warming melts ice bare soil, open water do not reflect as much radiation warming accelerates

COSC 4126 cybernetics Feedback and control in homeostatic systems equilibrium range stress breakdown hypothermia shivering normal sweating hyperthermia example: body temperature

COSC 4126 cybernetics Cybernetics in games  many feedback loops are embedded in games  comparators decide action in some loops, the comparator is the player

COSC 4126 cybernetics input acts to produce effect/result state change display output player activates or not goal “Core mechanic” the basic action cycles of a game  exclude peripheral actions like set-up  focus on core activity of game can often be analyzed as feedback loops with player as ‘comparator’ game dynamics

COSC 4126 cybernetics “Core mechanic”  purpose low level skill to be mastered and automatic as quickly as possible  tool for higher level play – Sims “inefficient” activity in the magic circle?  learning it is key to fun and meaning  typically real-time  e.g., driving game

COSC 4126 cybernetics Analysis of the feedback loop input acts to produce effect/result state change display output player activates or not goal game dynamics 1. game dynamics a) state evolves independent of player b) game reacts to player c) only player causes state change

COSC 4126 cybernetics Analysis of the feedback loop input acts to produce effect/result state change display output player activates or not goal game dynamics 2. timing of feedback loop - delay player sees display of state change of input n before deciding action n+k

COSC 4126 cybernetics Analysis of the feedback loop input acts to produce effect/result state change display output player activates or not goal game dynamics 3. input is discrete, “continuous” player explicitly generates each input; how difficult is the input action?

COSC 4126 cybernetics Analysis of the feedback loop input acts to produce effect/result state change display output player activates or not goal game dynamics 4. effect of input state change is deterministic, risky or uncertain?

COSC 4126 cybernetics Analysis of the feedback loop input acts to produce effect/result state change display output player activates or not goal game dynamics 5. discernability display shows all effect on state of player input?

COSC 4126 cybernetics Analysis of the feedback loop input acts to produce effect/result state change display output player activates or not goal game dynamics 6. comparator decision complexity high level control: is goal fixed or changing? how many input alternatives?

COSC 4126 cybernetics Summary of feedback loop factors 1.game dynamics 2.timing of feedback loop – delay 3.input is discrete, “continuous” 4.effect of input 5.discernability 6.comparator decision complexity

COSC 4126 cybernetics Example: driving a vehicle homeostatic system controlled travel veer or skid left veer or skid right crash left crash right focus on control focus on goal

COSC 4126 cybernetics Example: driving a vehicle feedback loop

COSC 4126 cybernetics Designing the core mechanic feedback loop game dynamics 2.timing of feedback loop – delay 3.input is discrete, “continuous” 4.effect of input 5.discernability 6.comparator decision complexity Two ‘tool’ examples 1.SnagIt 2.Office Draw

COSC 4126 cybernetics Feedback at higher levels Adjusting level to match player skill  Negative feedback adjust AI player skills – e.g., racing games adjust random probabilities “Dynamic Difficulty Adjustment” –Naughty Dog Entertainment dilemma of the magic circle – is adjustment fair? shown to be counterproductive in educational software

COSC 4126 cybernetics Feedback at higher levels Increase action and variety  Positive feedback introduces instability – e.g., oscillation  Monopoly cash flow reinforces differences  playoff scheduling  tennis seeding homeostatis – produces new equilibrium