Interactive Drama Dynamic Dialogue and Sandbox Worlds

Jason Hutchens AI Team Lead – Team Bondi Interactive Drama – Dynamic Dialogue and

Interactive Drama Dynamic Dialogue and Sandbox Worlds Interactive Drama – Dynamic Dialogue and Sandbox

ABOUT ME Research in Grammatical Inference and Data Compression. Worked at Lionhead Studios on Black & White. Former “Chief Scientist” of Artificial Intelligence Inc. in Israel. Recently joined Team Bondi as AI Team Lead. Interactive Drama – Dynamic Dialogue and Sandbox Worlds / AGDC © 2004 Team Bondi Pty. Ltd.

BLACK & WHITE Interactive Drama – Dynamic Dialogue and Sandbox Worlds / AGDC ©

SCOPE No State Machines, Scripting, A* or Flocking. Use AI to create a dramatic experience for the player. What can be achieved on Sony's next-gen console? Interactive Drama – Dynamic Dialogue and Sandbox Worlds / AGDC © 2004 Team Bondi Pty. Ltd.

ARTIFICIAL INTELLIGENCE A contentious term. Slippery to define Turing un-asked the question “what is intelligence” via his Test. We're specifically interested in behaviour that appears intelligent. Interactive Drama – Dynamic Dialogue and Sandbox Worlds / AGDC © 2004 Team Bondi Pty. Ltd.

INFORMATION THEORY Intelligent behaviour is unpredictable yet relevant. Eliminate randomness and repetition – maintain reasonable surprise. Behaviourism predicts the “slot machine” phenomenon. Interactive Drama – Dynamic Dialogue and Sandbox Worlds / AGDC © 2004 Team Bondi Pty. Ltd.

EXAMPLE Stochastic language models generate unpredictable sentences: Mega. HAL: WITHIN MY PENGUIN LIES A TORRID STORY OF HATE AND LOVE. Keyword-based generation helps to make them relevant. User: In 1793 the french king was executed. Mega. HAL: HA HA! CORRECT. ALTHOUGH, EXECUTED HAS MULTIPLE MEANINGS. Users talk to this thing for hours on end, and respond emotionally. Interactive Drama – Dynamic Dialogue and Sandbox Worlds / AGDC © 2004 Team Bondi Pty. Ltd.

SANDBOX WORLDS Graphics got fast and detailed, so players wanted more interaction. Physics improved, and is now practically mandatory. It's fun to “muck around” within these “sandbox worlds”. AI required to populate the world with believable characters. Interactive Drama – Dynamic Dialogue and Sandbox Worlds / AGDC © 2004 Team Bondi Pty. Ltd.

INTERACTIVE DRAMA All the world's a stage – add a compelling story to the mix. Façade, by Mateas and Stern, is an example (Interactive. Story. net). Dialogue is a necessary component. AI required to present the story, and process the dialogue. Interactive Drama – Dynamic Dialogue and Sandbox Worlds / AGDC © 2004 Team Bondi Pty. Ltd.

AUDIENCE OR PROTAGONIST? Cut-scenes are non-interactive and quickly become repetitive. Sandbox worlds lack dramatic tension. Rather than “being” the protagonist, the player may “act” in their role. AI required to interpret player action with respect to its context. Interactive Drama – Dynamic Dialogue and Sandbox Worlds / AGDC © 2004 Team Bondi Pty. Ltd.

GAME AI Typically, only 5% of resources spent on AI. We'll soon have the power of a desktop PC of the early 1990's. Create a compelling experience on such technology. We need to look beyond the search-and-optimise of GOFAI. Interactive Drama – Dynamic Dialogue and Sandbox Worlds / AGDC © 2004 Team Bondi Pty. Ltd.

SUMMARY AI is required to populate the world with believable characters. AI is required to present the story. AI is required to process the dialogue. AI is required to interpret player action. Interactive Drama – Dynamic Dialogue and Sandbox Worlds / AGDC © 2004 Team Bondi Pty. Ltd.

THE CHALLENGE Interactive Drama – Dynamic Dialogue and Sandbox Worlds / AGDC © 2004

ARCHITECTURE Interactive Drama – Dynamic Dialogue and Sandbox Worlds / AGDC © 2004 Team

PLAYER MODEL Interactive Drama – Dynamic Dialogue and Sandbox Worlds / AGDC © 2004

PLAYER MODEL Requirement: Interpret player action. Goal: Balance player freedom with narrative consistency. Goal: Enable cinematic presentation of gameplay sequences. Abstracted commands – context provided by story, world and subject. Interactive Drama – Dynamic Dialogue and Sandbox Worlds / AGDC © 2004 Team Bondi Pty. Ltd.

DIALOGUE ENGINE Interactive Drama – Dynamic Dialogue and Sandbox Worlds / AGDC © 2004

DIALOGUE ENGINE Requirement: Process the dialogue. Goal: Ubiquitous, believable conversations. Voice acting, localisation and input devices limit the possibilities. Move beyond menu-based conversation and “taunts”. Interactive Drama – Dynamic Dialogue and Sandbox Worlds / AGDC © 2004 Team Bondi Pty. Ltd.

DIALOGUE ENGINE Adopt Mann's “Dialogue Macrogame Theory”. A conversation is a sequence of short dialogue games. Players take turns speaking, and negotiate game entry and exit. Dialogue Engine moderates the games, and issues potential actions. Interactive Drama – Dynamic Dialogue and Sandbox Worlds / AGDC © 2004 Team Bondi Pty. Ltd.

DRAMA MANAGER Interactive Drama – Dynamic Dialogue and Sandbox Worlds / AGDC © 2004

DRAMA MANAGER Requirement: Present the story. Goal: Select a story thread and direct other components. Provide potential dialogue games to the Dialogue Engine. Constrain the behaviour of the Player Model and the Cast. Inform the Camera, etc. Interactive Drama – Dynamic Dialogue and Sandbox Worlds / AGDC © 2004 Team Bondi Pty. Ltd.

STORY ENGINE Interactive Drama – Dynamic Dialogue and Sandbox Worlds / AGDC © 2004

STORY ENGINE Requirement: Present the story. Goal: Provide potential story threads to the Drama Manager. Story threads specify cast, dialogue, locations, props, etc. Story Engine selects relevant story threads opportunistically. Each thread is a network of potential dramatic moments, or “beats”. Interactive Drama – Dynamic Dialogue and Sandbox Worlds / AGDC © 2004 Team Bondi Pty. Ltd.

CAST MANAGER Interactive Drama – Dynamic Dialogue and Sandbox Worlds / AGDC © 2004

CAST MANAGER Requirement: Populate the world with believable characters. Goal: A world of 1. 5 million inhabitants. Goal: Embodied, autonomous, reactive and conversational NPCs. “Extras” provide background, and ad lib when necessary. “Heroes” participate in the overarching story. Interactive Drama – Dynamic Dialogue and Sandbox Worlds / AGDC © 2004 Team Bondi Pty. Ltd.

CAST MANAGER NPCs have personality, emotion and a hierarchy of relationships. Extras are spawned at “random”, according to demographics. Extras behave reactively, foraging the environment and exiting ASAP. Heroes are hand-crafted, and inhabit the world persistently. Heroes behave deliberatively, as specified by story and routine. Interactive Drama – Dynamic Dialogue and Sandbox Worlds / AGDC © 2004 Team Bondi Pty. Ltd.

WORLD MODEL Interactive Drama – Dynamic Dialogue and Sandbox Worlds / AGDC © 2004

WORLD MODEL Provide world knowledge to Story Engine and Cast Manager. Manage non-story events that occur throughout the world. Provide appropriate dialogue games for talking about them. Interactive Drama – Dynamic Dialogue and Sandbox Worlds / AGDC © 2004 Team Bondi Pty. Ltd.

WORLD MODEL Adopt Milgram's “Six Degrees of Separation”. A “grapevine” extends from the NPC to an item of world knowledge. Probability of existence may be estimated. Each NPC appears to have their own knowledge of the world. Interactive Drama – Dynamic Dialogue and Sandbox Worlds / AGDC © 2004 Team Bondi Pty. Ltd.

CONCLUSION Suspension of disbelief requires believable worlds. Technology only worth using if it enhances the player's experience. We have the resources to build an AI team to achieve them. And the opportunity to create a groundbreaking, immersive game. Jason. Hutchens@gmail. com Interactive Drama – Dynamic Dialogue and Sandbox Worlds / AGDC © 2004 Team Bondi Pty. Ltd.