Fundamentals of Game Design, 2 nd Edition by Ernest Adams Chapter 20: Artificial Life and Puzzle Games

Fundamentals of Game Design, 2nd Edition

by Ernest Adams

Chapter 20: Artificial Life and Puzzle Games

Chapter 20 Artificial Life and Puzzle Games 2© 2009 by Pearson Education, Inc

Objectives

Know the different forms of artificial life games and simulations

Design basic artificial life systems Know the steps to designing puzzle games Understand the player’s needs for puzzle

games


Artificial Life Games

Artificial life is a branch of computer science research

A-life involves modeling biological processes A-life is the study of emergent properties—

unanticipated qualities or behaviors that arise out of the interactions of complex systems

A-life games typically focus on maintaining and growing a manageable population of organisms


Artificial Life Games (Cont.)

Artificial pets They can be simulations or fantasy pets Almost always cute; seldom reproduce or die Gameplay concentrates on training, maintenance,

and watching the creatures Pet needs a lot of AI

Variety of triggers and behaviors Show the pet's emotions through behavior



Artificial pets (cont.) Player influences pet's emotions through

interaction Pet should interact meaningfully with other pets Pet must be able to learn Rich AI distinguishes artificial pets from other A-

life Artificial pet is a software toy—no victory condition



The Sims Player controls the sims physically and indirectly

affects their relationships Each sim has a personality Cross between an artificial pet and a CMS—game

has an economy



The Sims (cont.) Needs

Each sim has six needs that must be met Needs drive the sims' behavior Need-based AI is the heart of most simple behavior

simulations Skills

Sims (in the first edition) have six skills they can improve Sims teach themselves skills Time management is critical



The Sims (cont.) Personalities

Game tries to simulate relationships among individuals Variables define each sim's personality and how they

react to each other Success of The Sims is based on the

unprecedented scope for creativity it offers and its emphasis on interpersonal relationships



Defining affinity between two characters: The “I Can’t Stand” Rule – A character cannot

stand another character who has an attribute above a certain threshold

“Birds of a Feather” Rule – Characters with high levels of one attribute are attracted to others with a high level of the same attribute

“Opposite Attract” Rule – Characters with high levels of one attribute are attracted to others with a low value for the same attribute



God games Characteristics

Player is a god with limited powers who gets more power from simulated worshippers

Omnipresent interaction model and an aerial perspective They often share qualities with CMS (indirect control of

population) and real-time strategy (compete directly against a rival god) games



God games (cont.) The economy of god games

Player’s power (mana) grows with the number and prosperity of his worshippers

Size of the population influences the maximum amount of mana the player may have and the rate at which mana is restored when it is below maximum

Positive feedback can be limited in various ways: People do not reproduce instantaneously Making land suitable for population growth costs mana Mana cost of using higher-level powers rises exponentially



God games (cont.) Gameplay in god games

Primary challenge is to produce population growth He must also damage the other god’s worshippers and

repair the damage the rival god does to the player’s people

To design a god game, start with the question of what powers you would like the god to have

A god game needs a lot of interesting animations for the people



Genetic A-life games Characteristics

They are about managing a population over time Player tries to achieve goals for the whole population Can’t concentrate too much on individuals

Designing a genome Genome defines the creatures’ inheritable

characteristics such as eye color, hair color, height, etc. Alleles are traits inherited from each parent

If parents have different traits, usually one wins—brown eye allele dominates blue eye allele



Genetic A-life games (cont.) Mutation

Change to the gene caused by an environmental factor Mutations may benefit the population by introducing

random new values into the gene pool Life span, maturity, and natural selection

Each creature needs a natural life span To evolve through natural selection, creatures must

have a time of immaturity before they can reproduce Genetic mutations that cause death in children do not get

passed on because children do not reproduce



Genetic A-life games (cont.) What does the player do?

Create new individuals and add them to the population to see how their genes influence the population

Add and remove environmental hazards that would weed out certain genes

Play with the rate and nature of mutation by adding or modifying mutagenic objects or areas of the environment

Mate individuals to select for particular characteristics


Puzzle Games

Characteristics In puzzle games, puzzle solving is the primary

activity Puzzle games usually provide related challenges,

variations on a theme The types of puzzles offered include pattern

recognition, logic, or understanding a process The puzzles give the player clues that have to be

solved to meet the victory condition


Puzzle Games (Cont.)

Find inspiration Simplify Create a construction

set Define the rules

Construct the puzzles Test Devise a sequence Pay attention to

presentation

Scott Kim’s eight steps in puzzle game design



What computers bring to puzzles Enable nonphysical or awkward moves Include computation features Enforce the rules Record player moves and undo them Structure the experience Teach Use bells and whistles Enable online play



Checking the victory condition Path to the solution might be different than you

planned Check the solution, not the way it was reached


Summary

You should now understand How to identify an artificial life game and

simulation How to design basic artificial life systems How to describe the steps to designing puzzle

games How to explain the player’s needs for puzzle

games

Documents

Fundamentals of Game Design, 2 nd Edition by Ernest Adams Chapter 20: Artificial Life and Puzzle Games