Interactive Storytelling(4190.420 Computer Game)

Jehee Lee

Seoul National University

Storytelling

• Storytelling was a natural, almost inevitable consequence of human evolution

• Why is storytelling such an important component of culture?– Stories are the vehicle by which cultural knowledge is

communicated from one generation to the next

• Why should information be transmitted by stories?– The information context pertains to social reasoning

and interpersonal behavior

Narrative

• Social relation, associative, parallel, pattern-type information is difficult to serialize and communicate

• Narrative is a reformatter that converts the information to a serial format

• A story is definitely a linear sequence of events, called plotline

Nature of Stories

• Strong structure– The conventional structure of stories

• Stories are about people

• Conflicts and choices keep the story going forward

• Stories take place on stages, not maps

Granularity of Stories

• The story is composed of story granules, such as bits, scenes, and sequences– Bits are the shortest– Scenes is longer in length. The scene is the shortest

unit that can convey the context of an event– Bits and scenes combine with each other to form

sequences

Plot versus Interactivity

• Andy Cameron– I will argue that there is a central contradiction within

the idea of interactive narrative—that narrative form is fundamentally linear and non-interactive. The interactive story implies a form which is not that of narrative…

– In a narrative, this notion of significance seems inversely defined, since the ability to alter events in the plot actually works to diffuse the significance of the story. If viewers can change characters’ actions with the wave of their hands, why should they care about the story? What indeed then is the story?

Plot versus Interactivity

• Andrew Grassner– The popularity of the concept of interactive fiction for

computer-based stories and games is surprising. Is there anything compelling in our cultural history that suggests people want to participate in received stories? Are there stunning examples of successful interactive fictive experiences that have turned doubting Thomases into true believers? NO.

– It’s the Myth of Interactivity again – recall that this myth tells us: Interactivity make games better, and a game designer should try to make the experience as richly interactive as possible. … This belief in the universal power of interactivity is what leads people to try to marry interaction and storytelling

Plot vesus Interactivity

• Plot and interactivity are incompatible

• Can we consider “metaplot”?– Something higher, more abstract than plot– Specified by rules and concepts, not by a sequence of

events

Choices in Interactive Storytelling

• A storyworld is composed of closely balanced decisions that can reasonably go either way

• The storybuilder’s most important task is creating and harmonizing a large set of dramatically significant, closely balanced choices for the player

Paring away the boring decisions

• Some important decisions may eliminate a series of subsequent (dramatically unimportant) decisions

• We may bundle them together as inevitable outcomes

• For example, the gap between the protagonist dropping his gun and finding himself in the dungeon should be minimized

Interesting Storyworld

• The story builder’s task in interactive storytelling is to envision a dramatic storyworld, not a storyline

• A storyworld of Arthurian legends– A large and varied collection of stories already exists

within literature

• The Lineage doesn’t use the storyline of the original comic book

• If you start with a single dramatic storyline, for example Romeo and Juliet, the single storyline will dominates your thoughts

Interesting Storyworld

• A storyworld is a much larger creation than a story

• A single playing of any storyworld generates a single story– The player’s path is a linear sequence of events– The listener would perceive the player’s experience

as a story

Atoms of Interactive Storytelling

• A substory is a single dramatic step• It is an event or a change• It can be described in a sentence

– Tiny event: “James sidestepped the descending sword and swung to his right.”

– Big event: “James killed Thomas in a swordfight.”

• Substories aren’t measured with a clock– Stories don’t move forward in synch with the clock– “Jan realized the significance of the white dog.”– “Andre lived happily in his new life, until one day …”

Dramatic Resolution

• Some decisions are significant, and some are not

• Restricting a storyworld to only gigantic decisions keeps things too simple to be interesting

• Ideally, every experience, thought, and perception should be treated as a substory and presented to the player.– Too much work for the story builder and the player

Game and Storytelling

• Games do not necessarily deliver stories

• Interactive storytelling and games with stories are close cousins– There are a number of successful games with

interesting stories– Have you ever seen any successful interactive drama?

Branching Trees

• Different plot based on each decision

• Exponentially increasing number of scenes

• Very difficult to create many good scenes

Bifurcating Plotlines

• The Garden of Forking Paths– In Ficciones (1944), Jorge Luis Borges– He was interested in bifurcating plotlines, but didn’t

want to spend his energy for righting uselessly long stories

Foldback Schemes

• It simply folds the storyline back to some predetermined path

• Lots of choices, but choices don’t really matter

Constipated Stories

• Lots of choices may be offered– One takes you forward– Some lead to death– Some are side trips– Some lead you back

• Usually artificially limit choices– Desert island– Boat– Spaceship

Peeping

• Many things happening, but can only view one at a time

• Can’t change what happens

• Been done as a live-action play

Linear with Puzzles

• Open world with puzzles that block your way

• Puzzles should be solvable from story

• No real choices in outcome• Myst, 7th guest, …• Puzzles are sometimes

replaced by shooting/action games

Start

End

Watch Some Video

Solve Puzzle

Watch Some Video

Solve Puzzle

Linear with Puzzles

• Puzzles should be related to plot– 7th guest had puzzles that had nothing to do with story

• Puzzles should be solved by what is available in the game

• Game shouldn’t take 4 weeks with 40 minutes of material

Open Environment

• The player explores and interacts with world

• Role playing games• Hard to have any plot or drama

Video versus Animation

• Live action video– Repetition of scenes – obvious & unnatural– Takes lots of CD space– Easier for long linear scenes– More realistic

• Animation– More flexible in action and special effects– Easier to splice in extra action– Can control detail of characters

A Man’s Love Story

• Interactive Drama with Live Action Footage– Scene-based granularity level– No predetermined plotline– Many independent scenes

Video-Based Conversational Agents

• Speech Animation– Dido.mov– Speech.avi

• The illusion of a conversation with video characters– http://www.idrama.com

Smart Synthetic Characters

• Should non-player characters in interactive drama be intelligent?

• Plot-orientated versus character-orientated– We may specify all the branches of plotlines, or– We may design lots of smart characters with

personalities and allow them to interact with each other

• Characters get smarter, less plotlines should be specified

Multi-User Games

• Solves problem of developing interesting characters

• Hard to have narratives• A massively multi-user game creates a society,

in which interesting events happen• The interaction among players can make stories

Emergent Game Design

• Games as Complex Systems(a lot of slides stolen from a GDC2000 talk by Mahk)

RulesInput Output

(Player)

(Graphics/Sound)

The “State Machine” Model

Definition

• Emergent Complexity (“Emergence”)– Properties that cannot be simply inferred from a

system’s rules

• Complex System– A system that possesses or exhibits emergent

complexity

Example: Conway’s Game of Life

Rules:• A grid of cells, each cell is either “alive” or

“dead.”• Each cell has 8 neighbors.• Count each cell’s live neighbors

– 2 or 3: Stay alive– Exactly 3: Become alive

This is called a “Cellular Automaton.”

Conway’s Life is a Complex System

• Static Patterns: Block, Honeycomb• Dynamic Patterns: Blinker• Moving Patterns: Glider• Patterns of Patterns: Beehive, Glider Gun

The rules are inadequate to describe the system’s behavior

Examples in Games

• Chess: Attack & Defense, Discovered Check, Knight Fork, etc.

• Go: Eyes, Life & Death patterns, Tesuji• Magic: The Gathering: Card Combos, Deck

Archetypes

Models of Complex Games

• Individual elements are simple• Rich interactions• Game state has many elements• Random initial conditions

Complexity does not mean lots of rules

A Brief Taxonomy of “Fun”

• Sense– Game as sense-pleasure

• Fantasy– Game as make-believe

• Narrative– Game as drama

• Challenge– Game as obstacle course

• Fellowship– Game as social framework

• Discovery– Game as uncharted territory

• Expression– Game as self-discovery

What makes Emergent Complexity “fun?”

• Discovery– The emergent properties of the system form an

explorable space– More complexity means more space

• Challenge– A game’s emergent properties form its “strategic

vocabulary.”– New scenarios and obstacles can emerge.

• Narrative (?)

Emergence and Narrative

• Narrative emerges from game events– Complexity gives you infinite monkeys

• Emergent and Embedded Narratives– Emergent narrative occurs as short vignettes– Embedded (Authored) narrative works well for major

story arcs

Perils of Emergence

• Contradictions are common, creating absurd fantasies

• Simulation reveals flaws & side effects• Degenerate strategies• Unintended feedback systems.

• Overly stable• Overly unstable