Information 2 Robin Burke GAM 224 Spring 2004

Outline Admin Systems of information Cybernetics Feedback loops

Admin Assassin new rules (see defrag.depaul.edu) deadline to join: Friday game starts: Monday "Rules" paper due: 10/10 = 12 days start to identify thesis / analytic angle

Information Information theory says that information is a quantity measured in bits based on the ambiguity of the situation Says nothing about how messages are generated or interpreted

Interpretation Irrelevant to information theory Crucial if we want to understand information in games Example Game behaviors are more meaningful if the player can discern success and failure the behavior has a direct connection to the overall outcome The game must communicate to the player "you did it wrong" "you're close to winning" Game must lead player to a correct interpretation

Semiotics 1 Meaning is encoded in signs verbal, gestural, sartorial, etc. Example architectural configuration the necktie a yellow ribbon

Semiotics 2 The sign has two parts signifier the expression that is made signified what the expression represents The meaning of a signifier is conventional "ya" means "I" in Russian, but "yes" in German hitchhiker's gesture

Semiotics 3 Decoding a sign is interpretation How the sign is interpreted depends on the interpreter the context Games establish a context for signs words, actions, symbols, visual cues the designer creates signifiers for the important elements of the game the player must learn to extract their meaning

Semiotics 4 Meaning is created by the interpretation of signifiers in context A game designer creates a new context with new meanings using particular signifiers But not in a vacuum signifiers are usually borrowed from the wider culture the design may rely on aspects of their conventional meaning

Example: Chess Signifiers shapes of pieces names for pieces Cultural Meanings powerful societal roles In-Game Meanings ability to move ability to control space Think about the "King"

Example: Almost every FPS Signifiers red cross Cultural Meaning sign for hospital In-Game Meaning an opportunity to recharge "health meter"

Systems of signs Signs do not stand alone signs are interpreted in the context of other signs Consistent semiotic structure makes your game easier to understand players enjoy decoding clues if there is a sensible pattern Example Mario Bro's Superstar Saga Enemies that can be attacked with electricity usually wear or carry something metallic.

From signs to information The interpretation of signs yields information Information about the state of the game about the game environment about what just happened about what might happen next

Systems of information Incomplete information makes for interesting gameplay why playing cards have a front and back Types of information public private hidden

Information economy Games of information often have an "information economy" a system through which hidden information is revealed private information becomes public Like all economies based on exchange

Example 1 Gin Rummy I don't know what cards my opponent holds If I discard a card and she picks it up private information is revealed but she is closer to winning Tradeoff benefit = knowledge of cards held cost = improved opponent position

Example 2 First-person shooter I don't know what opponents are in the next room or what the layout is If I walk in I'll learn what the opponents are but I might get killed Tradeoff benefit = tactical knowledge cost = risk of defeat

Information as reward Often information is a reward (more about rewards in "Play" unit) If you are successful in some action the game reveals more information If you take some extra effort to explore the environment Could be what to do next the location of something valuable a map etc.

Example

Information seeking Players will take action to gain information reduce uncertainty enable preparation / planning Meaningful choices arise when there are multiple ways to learn when those choices have different costs / consequences when those choices yield different kinds or qualities of information

Information revealing (Especially in multi-player games) Players may need to keep certain information hidden gain advantage over opponents Meaningful choices arise when exercising an option that might disclose valuable information in the possibility of deception

Game Design Issues What kinds of information are inherent in the design? What is the status of the information during the game? How is information communicated? How is hidden information revealed? What are the costs of information? What meaningful choices revolve around

Information Flow Systems have objects that interact Information is a quantity that objects in a system may exchange Weiner developed cybernetics to explain this type of system Cybernetics is an attempt to unify the study of engineered and natural systems

Cybernetic Systems Cybernetics is about control How is the behavior of a system controlled? Control implies that there are parameters that should be maintained Example: temperature human body car engine Control implies information Temperature messages "too high" "too low" "OK"

Feedback Loops Basic loop A cybernetic system needs a sensor that detects its state The information detected by the sensor is then compared against the desired value If the value is not correct, the system adjusts its state the sensor detects this new state, etc. The system maintains stability by feeding the information about its state back to the process producing the state

Two Types of Feedback Loops Negative Feedback Loop "inhibition" As the state changes, the loop acts to move it in the direction of its previous state Example thermostat Positive Feedback Loop "excitation" As the state changes, the loop acts to move it in the direction that it is moving Example automobile turbocharger home team advantage

Audio example

Feedback Loops in Games From book game state scoring function controllergame mechanical bias

Example game state state of a fighting game scoring function player's health controller near-KO bias increase chance of critical (high damage) hit on opponent

Effects?

Example 2 game state state of the chessboard scoring function the number of pieces taken controller for each piece taken bias add a pawn to the taker's side in any position

Effects?

Examples

Multiple Loops Games may have multiple feedback loops in operation Examples racing game a player who falls behind may be better power-ups AI racers may adjust their ability to keep pace with player RPG killing monsters gives experience points for gaining levels as a player gains levels, they gain better weapons and greater abilities more success at killing monsters, etc. but game is designed so advanced areas have tougher monsters levels get farther and farther apart

In General Negative feedback loops increases system stability makes the game last longer magnifies late successes Positive feedback loops destabilizes the system makes the game shorter magnifies early success

The Other Sense We also use the word "feedback" to mean praise vs criticism "I got some negative feedback on the proposal, so I'm revising it." This is not the same psychological sense of feedback information about the quality of something good or bad cybernetic sense of feedback a dynamic established by a system's structure that pushes its state in one direction or another in response to information

Game Design Issues Know what feedback is going on in your system analyze how game mechanisms combine to produce feedback Feedback may be undesirable negative feedback may make a successful player feel punished positive feedback may magnify ability differences between players

Monday Quiz #1: Rules Game design exercise