Practical Techniques for Implementing Emergent Gameplay

bouncerarcheryAI and Robotics

Nov 14, 2013 (3 years and 11 months ago)

145 views

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Practical Techniques

for Implementing

Emergent Gameplay


Would the Real Emergent

Gameplay Please Stand Up?

Randy Smith

rsmith@ionstorm.com

Harvey Smith

witchboy@gmail.com

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Intro


Harvey Smith

Deus Ex/Invisible War


Randy Smith

Thief 1/2/3



Ion Storm aesthetic goals

»
Improvisational (player
-
authored) gameplay

»
Benefits from large gameplay possibility space

»
Emergence provides more explorable space

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Our Topic


How to Add Meaningful Emergence
to Video Games


Topics that have been covered
elsewhere:

»
History of Emergence

»
Emergence and Narrative

»
Emergence and Uncertainty

»
Benefits and Costs/Risks of Emergence

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Focus


Less Theoretical, More Practical

»
Related to modern game system design

»
Skewed toward large
-
scale action games


Emergence within a game system
context

»
No player psychology, social influence, etc.

»
Focus on the system space of game


Power
-
ups, Weapons, Tools, Monsters

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Disclaimers


Emergent gameplay isn't necessary
to design good games


No holy wars, despite the
provocative title of the presentation

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Takeaway


A practical approach to creating
meaningful emergence in your own
game designs.



You are a game designer

»
You design game systems

»
You want to focus on emergent gameplay

»
How do you accomplish this?

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Outline


Preamble


Intro to Emergence


Creating Emergence


Creating Mechanics that result in emergent
game dynamics


Qualifying Emergence


Creating emergent gameplay that results in
meaningful game aesthetics


Wrapping Up


Q & A

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

I


Intro to Emergence


Definitions


Vocabulary


Examples

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

A Typical Real
-
World Definition


A discernable, higher
-
level behavior
of a system which is not immediately
obvious by looking at the low
-
level
rules that govern the system’s
behavior.



…let’s look at an example of real
-
world emergence

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Global Warming

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Global Warming

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Global Warming

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Global Warming

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Global Warming

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

MDA Framework


A rules
-
oriented approach to game design


Mechanics

The rules

of the game


Dynamics

Real
-
time rules interactions


Aesthetics

Human emotional responses

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Emergence in Video Games

(our definition)




A second order game Dynamic
created by the interaction of first order
game Mechanics.

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Example 01: GTA3


Player accidentally flips his car, which
explodes, injuring nearby pedestrians who
begin to attack him

»
Player takes a jump



»
Car flips and lands upside down



»
Car explodes



»
Nearby pedestrians are injured by explosion



»
Pedestrians begin to attack player

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Example 01: GTA3


Player accidentally flips his car,
which explodes, injuring nearby
pedestrians who begin to attack him

»
Player takes a jump



»
Car flips and lands upside down



»
Car explodes



»
Nearby pedestrians are injured by
explosion



»
Pedestrians begin to attack player


Note that there is no explicit
Mechanic describing
this

behavior

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Example 02: Tactical Shooter


Indirectly Connected game Mechanics

»
Gas barrels Leak poison when ruptured

»
Poison Kills enemies and players

»
Bullets Kill enemies, and Rupture gas barrels

»
Weapons Fire bullets when dropped

»
Enemies Fire bullets, and Drop weapons on death


Player shoots guard


guard drops gun


gun goes off when it hits the ground


bullets rupture barrel


poison leaks out


poison kills other enemies

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Example 03: Thief


In order to injure a nearby guard, player
ignites an oil puddle by knocking a candle
off a table

»
Player throws a box at a table


»
Table wobbles


»
Candle falls off table


»
Candle falls into oil puddle


»
Oil puddle ignites


»
Nearby guard is injured by the flames

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

MDA Framework

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

MDA Applied to Emergence


Mechanics

»
The rules

of the game

»
You modify Mechanics to alter emergent
interactions


Dynamics

»
Real
-
time interactions between Mechanics

»
Mechanics connecting to each other

»
Where emergence happens


Aesthetics

»
Human emotional responses

»
Wider exploration space, emergent narrative

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

II


Creating Emergence

Quantitative


Mechanics


Connecting Mechanics Together


Relevant Technology


Populating the world with Mechanics

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Where Mechanics “Live”


Power
-
ups

»
“When guns hit the ground, they fire off bullets”


Environmental Objects

»
“When barrels are damaged, they release poison
gas”


Simulations

»
“Cars can flip upside down when they land from
jumps”


Autonomous Agents

»
“If pedestrians take damage, they attack whoever
is responsible”


Etc.

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

more about


Autonomous Agents


Can act independently, possibly react
dynamically to situations


Guard AIs in Deus Ex and Thief


Cars and Pedestrians in GTA3


The Bat in Adventure


Special properties


Emergence without direct player intervention


Make the world feel alive


Create dynamic situations

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Creating Emergence by Adding
Indirect Connections


Emergence fails to happen when
Mechanics aren’t indirectly
connected


Emergence can be created by adding
more indirect connections


making
the Mechanics “listen to” each other

»
Guard with torch slips on oil puddle


»
Guard falls to the ground

»
Nothing else happens

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Creating Emergence by Adding
Indirect Connections


Emergence fails to happen when
Mechanics aren’t connected


Emergence can be created by adding
more connections


making the
Mechanics “listen to” each other

»
Guard with torch slips on oil puddle


»
Guard falls to the ground


»
Guard drops torch


»
Torch ignites oil puddle


…let’s talk more about connecting
Mechanics

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

The Tactical Shooter Example


Indirectly Connected Game Mechanics

»
Gas barrels leak poison when ruptured

»
Poison kills enemies

»
Bullets Kill enemies, and Rupture gas barrels

»
Weapons Fire bullets when dropped

»
Enemies Fire bullets, and Drop weapons on death

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Visualizing All Mechanics

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

-
1 Mechanic

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

-
2 Mechanics

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Getting Mechanics to Connect


Again, it helps to have a rules oriented approach


It’s tempting to spam the world with Mechanics,
to pile them on


Mechanics are independent, but indirectly
connected


Some Mechanics are more highly connected


How do you get the best return on your
investment?


Choose Mechanics that have relationships to
each other

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Example from DX:IW:

Choosing Where to Invest


Prismatic Resonator Biomod

»
Fewer Indirect Connections


Beam Triggers (3 types)


Bot Domination Biomod

»
More Indirect Connections


All robots (8 types), Cameras, Turrets, Spiderbombs

»
Bots are improvisationally useful for combat, door
opening, setting traps, etc


Players started using spiderbombs to open doors

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Player Improvisation


Players ‘Unlocked’ Doors with Spiderbombs


Indirectly Connected Game Mechanics

»
Spiderbombs


Spawn Spiderbots

»
Spiderbots


Obey All Bot Rules


Susceptible to Bot Domination


Susceptible to EMP


Explode If Damaged Post
-
EMP

»
Bot Domination


Possess Bots


EMP Bots Post
-
Ejection

»
Doors


Can Be Locked/Lockpicked


Destroyed By Explosions

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Player Improvisation

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Invest in Related Mechanics


If you’ve already got these Mechanics:

»
Flamethrower can catch enemies on fire

»
Burning enemies can catch furniture on fire


Add more elements and Mechanics having to do
with fire, e.g.:

»
Fire extinguishers

»
Oil puddles

»
Dynamite

»
Candles

»
Water arrows

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Supporting Technology


Takeaways

»
Some technology supports the
implementation of emergence better than
others

»
Need to work with technologists to
evaluate your technology status

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Supporting Technology


Explicitly hard
-
coded Mechanics are messy and
difficult to support


You might forget to implement one of them

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Supporting Technology


The Stimulus System is a generalized way for
objects to listen to each other


You can describe objects intuitively

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Supporting Technology


Easier to create and modify connected
Mechanics


More reliable and likely to create
improvisational emergence

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Ion Storm’s Supporting
Technology


Stimulus System

»
Generalized channel for objects to listen to
each other

»
Don’t have to explicitly hard
-
code Mechanics


Property System & Object Hierarchy

»
Quick and easy creation and editing of objects


Scripting System

»
Quick and easy to describe resulting behaviors

»
Oil puddle: “When I receive fire stim, turn into a
fire puddle”

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Populating the world with
Mechanics


For Mechanics to connect, they
typically have to exist in physical
proximity to each other.

»
How rich is your world with Mechanics?
E.g.


how many gas barrels exist in your
world?

»
How often are the connected Mechanics in
proximity to each other? E.g.


do you
ever place guards near gas barrels?

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Examples of World Population
from Thief


Negative example

»
Fire elementals that re
-
light torches when guards
are nearby in Thief

»
Good idea, but Fire elementals and Guards /
Torches were never in the same levels

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Examples of World Population
from Thief


Positive example

»
Player shoots arrow at a candle to knock it
over


arrow misses and hits metal door
instead


nearby guard hears sound and
comes to investigate

»
Physical surface, Sound Propagation, and
Lighting house Mechanics in Thief

»
..and they populate the world exhaustively.

»
What elements already exist in your world
which you can add Mechanics to?

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

III


Qualifying Emergence

Qualitative


Aesthetic Goals


Meaningful Emergence


Involving the Player

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

What are your Aesthetic Goals?


What do you hope for emergence to
contribute to your game?

»
Deus Ex = Empower many emergent
solutions

»
Thief = Creating the occasional sublimely
tense moment of emergent challenge

»
GTA3 = Simulate a dynamic, responsive,
living world; Enable emergent mayhem

»
All three = Authoring your own experience
(emergent narrative)

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Meaningful Emergence


In accordance with aesthetic goals


The player perceives the events


Impact on gameplay experience, Not
just some wacky outcome

»
No gameplay relevance: Prox mine wall
climbing

»
Gameplay relevance: Spider bomb door
unlocking


Meaningful to the fantasy

»
Violates fantasy: Age of Empires sheep

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

How involved is the player?


Does the player have input into the Mechanics
which create emergence?


Theoretical Game: There is a factory with lots of
robots interacting emergently. If they touch you,
you die, but they don’t react. Get to the other
side.

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Robot Factory Game

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Player Perception of Emergent
Experiences


Reactive


does not require player input

»
“Emergent challenge”


a challenging situation that
develops emergently

»
E.g.


the previous robot factory example

»
E.g.


pedestrians in GTA3 turn hostile toward the
player

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Player Perception of Emergent
Experiences


Proactive


player must provide
input

»
“Emergent solution” or “Emergent
strategy”


the player creates their own
solution to a problem by leveraging their
understanding of the game’s emergence

»
E.g.


igniting oil puddles by knocking a
candle off a table in Thief

»
E.g.


player runs over pedestrian to
summon ambulance for ambulance
missions in GTA3

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

IV


Wrapping Up


Design Process


References

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

Emergent Gameplay Design Process


Aesthetic Goals

»
Widening possibility space via emergent systems


Technology Considerations


Plan Game Systems

»
Player agent(s), tools, traps, resources, etc.

»
Decide where to invest, Disregard low connection Mechanics


Populate world with Mechanics


Evaluate system Dynamics

»
Quantitatively


Litmus test

2
nd

order consequence?


Common enough?


Perceptible?

»
Qualitatively


Dynamics match the fantasy?


Did you meet your aesthetic goals?


Iterate

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com

References


Various References to Emergence

»
Marc LeBlanc’s GDC Lectures


Rules of Play

»
Book by Eric Zimmerman and Katie Salen


Dynamics for Designers

»
Will Wright’s 2003 GDC Lecture


Complexification

»
Book by John L. Casti


Emergence

»
Book by Steven Johnson

Practical Techniques for Implementing Emergent Gameplay

(Would the Real Emergent Gameplay Please Stand Up?)




rsmith@ionstorm.com

hsmith@ionstorm.com


Practical Techniques

for Implementing

Emergent Gameplay


Randy Smith

rsmith@ionstorm.com

Harvey Smith

witchboy@gmail.com

Q & A