Administrative

• This was the last homework for the semester (yay!)• First run of games: October 16nd in class

– Short document describing: goal + operational rules (1-2 pages)

– Main point: bring a working prototype • Even rudimentary and short• But needs to be interactive

– Class will be given a questionnaire for evaluating your game

– Answered questionnaire will be returned to game designers

– I’ll give pointed feedback of what needs to be done to be exempt from the final

Rules for Digital Games and Categorization of Games based on AI

(Ch. 13)

RECAP from previous class

• Characteristics of rules in games

• Rules in any game exists on 3 levels:

Rules limit player actionRules are explicit and unambiguousRule are shared by all playersRules are fixedRules are bindingRules are repeatable

Constitutive rulesOperational rulesImplicit rules

Now we are going to look at these definitions in the context of digital games

One Question

• Are the rules of a digital game the same as the program that codes this game (because if so why bother with rules levels and such…)?

Parts of the program that are unrelated to the rules of the game:

• “allocate” more memory for program• Load a software library to build complex

pieces of code• “garbage collection”• …

Example: Rules of Tetris

• Let us list the operational rules of Tetris– For this version

• Keyboard action are part of the game rules

• Randomness of next piece is an integral part of the rule design

Example: Rules versus Non rules in Digital games

Examples of “non rules”• Background in Tetris

• Are visuals part of the operational rules of games?

Example where the answer is “yes”: HW: Give an example of an element in the graphical

user interface of the game that is part of the game’s rules

Examples where the answer is “no” HW: Give an example of an element in the graphical

user interface that is not part of the game’s rules HW: Do they affect the experience?

Thief: Some Operational Rules

• Check the video

• Factors influencing NPCs detection:

– Lighting• Your location• Environment (torches)

– Proximity to NPC– Line of view of NPC– Your movement

Thus, visuals are an integral part of the operational rules for this game

Constitutive Rules for Digital Games

• Same constitutive rules as for non digital games– Why?

They concern with the game logic

Internal events (how choice is processed)

As opposed to external events (how choice is represented)

• Lets think of the constitutive rules for a digital Chutes and Ladders versus a non digital one. Any difference?

Operational Rules for Digital Games

• Include input devices (keyboard, etc)

• Lets think of the operational rules for a digital Tic-Tac-Toe (versus non-digital)

• Operational rules focuses on external events (how choice is represented)

Implicit Rules for Digital Games

• Examples of implicit rules in digital games? (HW)

Move mouse cursor movesPlaying the game won’t affect my computer!…

Categories of Games from an Artificial Intelligence (AI) Perspective

• Categories were, in part, the result of pursuing to apply AI techniques to construct “better” computer-controlled opponents

• Depending on the categories, building such AI turns out to be easier or more difficult

• They provide game design options– You can consider these options in the game you are

creating.

Deterministic Games

• Every player’s action results in a single pre-determined state?Yes: Deterministic game

state

action

Chance Games• Every player’s action results in a single pre-determined state?

No: Chance game

A

B

Action: A cast a damage spell on B

Outcome:• B blocks spell with

20% chances• If B does not block

spell, then damage dealt to B is randomly choose between 25%-40% of player’s B health pointsAction

state1

state2

…

(We don’t know apriori which until action is performed)

Perfect Information Games

• Does the player knows all information about the current state of the game?Yes: perfect information game

Imperfect Information Games

• Does the player knows all information about the current state of the game?No: imperfect information game

Categories of Digital Games (from “Artificial Intelligence” perspective)

Perfect information

Imperfect information

Deterministic Chance

Chess

Starcraft (*) Civilization

Chutes and Ladders

(*) assuming there is no hit/miss dice rolled when a unit shoots another unit