Game-makers who want to tell deeply-engaging stories must rediscover the power of ambiguity, and the power of the player’s imagination. This was the message from Sam Barlow, the British creator of the game Her Story, speaking at the Game Developer's Conference.

Her Story plays with narrative and chronology by applying the flexibility of video game structure with the ambiance of the murder mystery genre. Barlow explained that his 2015 game has been a triumph, not only in terms of critical and commercial success, but also in proving to the designer that, in the video game medium, a player’s brain is still the world's most powerful game engine.

“This game was an attempt to push a certain type of storytelling in an extreme direction to prove a point to myself,” he said. “It reinforces my belief that the directions in which I was pushing were fruitful.”

That power derives specifically from the player’s imagination, which is agitated by ambiguity in storytelling. In the game, players trawl a database as they try to piece together the story of a murder, told via 300 dispersed clips, spliced from a series of interview sessions with detectives. Players cannot access the clips in chronological sequence. Rather, they must use search terms to query the database. If a chosen term appears in the transcript of one or more clips in the database, it is presented for viewing. In this way you begin to dredge through the archive, gradually piecing together the story in a non-linear order.

Barlow, who had the idea of using found police tapes as a delivery mechanism for a story after watching Sharon Stone’s audition tapes for the film Basic Instinct, referenced Ernest Hemingway’s maxim that writers should only show the 'top of the iceberg', leaving the reader to use their imagination to fill in everything below the water, and therefore deepen their involvement in the story.

“When a player’s imagination adds the detail, the story becomes a lot more powerful,” he said. “The art is in not showing things.”

This is something that games generally do badly, said Barlow. “Modern video games are obsessed with continuous time and space,” he said. “All of the story beats are controlled by the player. This removes the ambiguity. We have less and less of a role for the imagination in this kind of game.”

Barlow pointed out that some of the problem is related to the fact that, if a game’s story is also the delivery mechanism for its mission objectives, then there’s no room for ambiguity; abstruseness becomes a user interface issue. “This is detrimental to telling an interesting story.”

Barlow began the creative process for Her Story, he explained, by writing a mission statement, in which he tried to outlay those aspects of interactive storytelling that felt special and unique to him. “I asked myself: ‘What is the stuff I do just because it feels like part of the template of making a video game?’ ‘What are the assumptions I can throw away?’”

He wrote a pitch to guide his thinking, that stated:

‘I will go deep on story, explore authentic and true characters. For my first trick I will make a game --

“I wanted to make a point that not only could we have a game that involved subtext,” he said, “but one that revolved around subtext.”

Barlow pointed out that interactivity in storytelling is not something that is unique to the game medium. “If you’re watching a movie you’re desiring some kind of outcome,” he said. “You might want the couple to get together, or the protagonist to get the bad guy. You’re thinking through the potential outcomes, willing the character to work in a certain way.

"If it’s well constructed, the character will do what you wanted, but there are unforeseen drawbacks. You then have feeling of complicity and guilt. I wanted to not pretend that interactivity is something that only games can do, but rather to look at how traditional storytellers have used dialogue with the listener and build on that.”

Her Story has a disordered structure. You’re finding a jigsaw, with clips of information that you put together in your mind. “You’re seeing clips, and your imagination is crunching trying to put the pieces together,” he explained. “But because the audience is highly familiar with genre, they have a tool set of the imagination when you work in a genre.”

Barlow also presented some ideas for how to create a greater level of investment, that might initially seem counterintuitive, “If you have a player who is deeply involved in your story, I’ve found that, if you push back against their engagement, there’s a Newtonian reaction where the player will work even harder to try to make things real,” he said.

“Twists are fantastic for this, as they reboot the simulation. Everything that came before will be seen in a new light. The imagination scurries to get everything up and running again, to convince you that it’s real.”