As games grow bigger in scope, writers are facing the ratcheting challenge of keeping NPCs individually interesting and realistic. How do you keep each interaction with them - especially if there are hundreds of them - distinct? This is where Ghostwriter, an in-house AI tool created by Ubisoft's R&D department, La Forge, comes in.
Ghostwriter isn't replacing the video game writer, but instead, alleviating one of the video game writer's most laborious tasks: writing barks. Ghostwriter effectively generates first drafts of barks - phrases or sounds made by NPCs during a triggered event - which gives scriptwriters more time to polish the narrative elsewhere. Ben Swanson, R&D Scientist at La Forge Montreal, is the creator of Ghostwriter, and remembers the early seeds of it ahead of his presentation of the tech at GDC this year.
The Beginnings of Ghostwriter
Ben's interest in creative applications of Natural Language Processing began while studying his PhD in Computer Science at Brown University, where he took a class with two creative writers from Brown and Rhode Island School of Design on Digital Literature. In this class, Ben was introduced to the idea of creating art using generative models and has since been exploring the possibilities of combining this technology and creative writing. This interest followed him to Google where he worked at Stadia Games and Entertainment in 2019, and then Latitude at AIDungeon, where he furthered his research in machine learning and published a paper on the subject in 2021.
In 2021, Ben became interested in joining Ubisoft, as he was intrigued by a GDC talk from the Watch Dogs team. "I actually saw a talk on the narrative design of Watch Dogs: Legion, and I was very impressed," he explains. "I thought to myself, 'I wish I was working on something like that with teams of professional scriptwriters,' so, I applied."
This fortuitous timing allowed Ben to connect with Ubisoft La Forge who had already been scoping for a solution to some of their technological questions. "It was perfect timing because they wanted someone to do exactly what I wanted to do."
Ben's wish to work with professional and like-minded teams became a reality as he began collaborating with members of the La Forge team in China, whose expertise in UX/UI and web application development resulted in a now operational tool: Ghostwriter.
Ghost of AI Present
Ghostwriter is the result of conversations with narrative designers who revealed a challenge, one that Ben identified could be solved with an AI tool. Crowd chatter and barks are central features of player immersion in games - NPCs speaking to each other, enemy dialogue during combat, or an exchange triggered when entering an area all provide a more realistic world experience and make the player feel like the game around them exists outside of their actions. However, both require time and creative effort from scriptwriters that could be spent on other core plot items. Ghostwriter frees up that time, but still allows the scriptwriters a degree of creative control.
"Rather than writing first draft versions themselves, Ghostwriter lets scriptwriters select and polish the samples generated," Ben explains. This way, the tech is a tool used by the teams to support them in their creative journey, with every interaction and feedback originating from the members who use it.
As a summary of its process, scriptwriters first create a character and a type of interaction or utterance they would like to generate. Ghostwriter then proposes a select number of variations which the scriptwriter can then choose and edit freely to fit their needs. This process uses pairwise comparison as a method of evaluation and improvement. This means that, for each variation generated, Ghostwriter provides two choices which will be compared and chosen by the scriptwriter. Once one is selected, the tool learns from the preferred choice and, after thousands of selections made by humans, it becomes more effective and accurate.
Challenges and Global Support
Teaming up with Ubisoft La Forge with this state-of-the-art tech did not come without challenges. AI in video games is not a new concept, with most associating this technology with NPC behaviors. Yet, this concept of machine learning is restrictive to its actual implications, as the industry now sees a place and need for not just AI tools, but machines that can learn through human feedback. Ben's research and work on Ghostwriter and his collaborations with teams across the globe have resulted in an AI infrastructure at Ubisoft that takes into account this potential, while working hand-in-hand with narrative designers to help kickstart their creative stories and games.
However, working with like-minded teams and getting the tool from conception to Ubisoft was only half the battle, as Ben says the focus has now shifted to supporting adoption by productions. By collaborating closely with scriptwriters, the team can learn their needs in order to better fit the tool into the unique worlds of each game. A tech like Ghostwriter requires scriptwriters to learn how to not only use the tool, but also integrate it in their video game production process.
The team's ambition is to give this AI power to narrative designers, who will be able to eventually create their own AI system themselves, tailored to their own design needs. To do this, they created a user-friendly back-end tool website called Ernestine, which allows anyone to create their own machine learning models used in Ghostwriter. Their hope is that teams consider Ghostwriter before they start their narrative process and create their models with a vision in mind, effectively making the tech an integral part of the production pipeline.
Future of Ghostwriter
Ben is very optimistic about Ghostwriter's later implementation in video games and believes in its role in the future of our games. Through its user-friendly interface and processes and its powerful AI infrastructure, scriptwriters who decide to include the tech in their production will eventually be able to scale up their games, be more ambitious in their narrative designs, all while having full control over their work.
Ben spoke more about this tool at GDC this year with his session titled "Machine Learning Summit: Natural Language Generation for Games Writing" on March 21 in San Francisco.
If you're interested in the future of tech at Ubisoft and want to have an impact like Ben did, you can find our open positions at jobs.ubisoft.com!