Homework for Next Class
Reading: Chapter 13
For a digital game of your choice (*):
1. Give an example of an element in the graphical user
interface of the game that is part of the game’s rules
2. Give an example of an element in the graphical user
interface that is not part of the game’s rules
3. Regarding your response to Question 2, does this
element affects the play experience?
4. Give an example of an implicit rule for this game
(*) describe this game in one paragraph including name,
what type of game it is - RPG, RTS, etc-, and what is the
objective of the game
Defining Rules and Levels of Rules
(Chs. 11 & 12)
Rules: Example
• Let us define the rules for Tic-Tac-Toe
• These rules describe the formal system (i.e., neither the
experience nor the cultural context)
• Does the game change if we use “” instead of “X”, and
“” instead of “O”?
– What about if we use a nice background?
– Does the experience change?
Characteristics of Game Rules
•Rules limit player action
•Rules are explicit and unambiguous
• Is this ambiguous: “roll the dice and move forward as
many positions as indicated by the resulting roll”?
•Rule are shared by all players
•Rules are fixed
– But high level players in RPGs can do stuff that lower
levels can’t. Does this means rules are not fixed in
RPGs?
•Rules are binding
•Rules are repeatable
Rules and Strategy
• We now know the characteristics of rules
• What is an strategy?
• What is the difference between an strategy and a rule?
Idea: Abstraction
• A non-gaming example:
Formulate a property or “formal structure” that is
common to the following 2 sets of numbers:
A = {2, 4, 6, 8, 10}
B = {1006, 1008, 1010, 1012, 1014}
• Formulating such properties provides a better
understanding of sets, models, and systems
• Surprisingly the same idea can be applied to games…
Another Game
• Lets play these two games:
– Tic-Tac-Toe
– “3-to-15” game:
• Two players alternate turns
“Operational • On your turn pick a number between 1 and 9
Rules”
that has not been picked before
• The first player to pick exactly 3 numbers that
add to 15 wins
• These two games have a common formal structure
– Don’t believe me? See next slide
Formal Structure or “Constitutive Rules”
for Tic-Tac-Toe and 3-to-15
2
9
4
7
5
3
6
1
8
Which is
more
appealing:
Tic-Tac-Toe
or 3-to-15?
Both games have the same constitutive rules:
•Players alternate making a unique
“Constitutive selection from a grid of 3 x 3
Rules”
•First player to select 3 in a row, column,
diagonal wins
•Otherwise, it is a draw
Level 1: Operational Rules
• They delineate precisely how a player manipulates and
interpret objects in the game
• Describe specific actions that player takes
• These are the rules that players read to understand what
is the game about
– These are the rules that are typically printed in the
manual or instructions of the game
Level 2: Constitutive Rules
• Describe the
mathematical logic of
the game
• Actions are more
general; can fit many
games
• Another Example:
“Chutes and
Ladders”
• We know the
operational rules
• But what are the
constitutive rules?
Constitutive Rules of “Chutes and
Ladders”
• Players begin with a
value of 0
• Players alternate
turns adding a
random number from
1 to 6
• First to reach 100
wins
• When player reaches
certain numbers
(e.g., 62) it adds or
subtracts a certain
amount (e.g.,
subtract 43)
Why not using rules close to the
constitutive rules?
• Why do we need the board in “Chutes and Ladders”?
– Why not use the 1-to-100 rules?
– Why this specific set of operational rules?
 Elegant design: no need for calculator
 Meaningful: discernable
 Meaningful: integrated
• What are the constructive rules for RTS, RPG, FPS
games?
– Some answers will be provided in the design
analysis project
– How can I tell if a set of constitutive rules is “right”?
 Those rules should be the same for any other
game in that Genre: Example 1 and Example 2
Level 3: Implicit Rules
• Unwritten rules. Examples for Tic-Tac-Toe?
–Fair play (“no cheating”!)
–Etiquette
–…
• Unwritten rules. Examples for Warcraft?
•Other examples:
 When teaching another player to play chess one may
avoid certain rules
• Sometimes an implicit rule is actually written. Example?
Summary
• Games are structured activities
Rules determine the structure
An integral part of game design is
therefore creating (and testing) the rules
Beta testing
Problems tuning rules can be game
breaking
• “More than a procedure for designing games, the three kinds of
rules provide a framework for understanding how rules operate”