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
activatoracts to produce effect/result
result
sensorcomparator
activates or not
goal
externaleffect
COSC 4126 cybernetics
coldoutside
Feedback for homeostatis Negative feedback: how a system
reacts to maintain stable condition
furnacegenerate heat temperature
of room
thermometerthermostat
activates or not
temperaturesetting
COSC 4126 cybernetics
Temperature control
time
goaltemperature
actualtemperature
furnaceoperating
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
activatoracts 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
activatoracts to produce effect/result
result
sensorcomparator
activates or not
goal
opposite conditionproduces 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
equilibriumrange
stress stressbreakdown breakdown
hypothermia shivering normal sweating hyperthermiaexample: 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
inputacts to produce effect/result state
change
displayoutput
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
inputacts to produce effect/result state
change
displayoutput
player
activates or not
goal
gamedynamics
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
inputacts to produce effect/result state
change
displayoutput
player
activates or not
goal
gamedynamics
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
inputacts to produce effect/result state
change
displayoutput
player
activates or not
goal
gamedynamics
3. input is discrete, “continuous”
player explicitly generates each input; how difficult is the input action?
COSC 4126 cybernetics
Analysis of the feedback loop
inputacts to produce effect/result state
change
displayoutput
player
activates or not
goal
gamedynamics
4. effect of input
state change is deterministic, risky or uncertain?
COSC 4126 cybernetics
Analysis of the feedback loop
inputacts to produce effect/result state
change
displayoutput
player
activates or not
goal
gamedynamics
5. discernability
display shows all effect on state of player input?
COSC 4126 cybernetics
Analysis of the feedback loop
inputacts to produce effect/result state
change
displayoutput
player
activates or not
goal
gamedynamics
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 dynamics2. timing of feedback loop – delay3. input is discrete, “continuous”4. effect of input5. discernability6. comparator decision complexity
COSC 4126 cybernetics
Example: driving a vehicle homeostatic system
controlledtravel
veer orskidleft
veer orskidright
crashleft
crashright
focus oncontrol
focus oncontrol
focus ongoal
COSC 4126 cybernetics
Example: driving a vehicle feedback loop
3 4
56
1
2
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Designing the core mechanic feedback loop
3 4
56
1
2
1. 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