Please say yes to a date (Image: Prom Week)

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CLASS nerd Zack wants to make friends with prom judge Naomi, but she doesn’t think he is cool enough. Luckily, Zack can improve his social standing by insulting Monica, a third character, who is not exactly Naomi’s favourite person…

Welcome to the world of Prom Week, a game about the social lives of high-school students that is powered by a “social physics” engine. Comme il Faut is an artificial intelligence system that tracks around 5000 social rules influencing a character’s behaviour and relationships.


Many video games use physics engines, which apply the basic principles of gravity, momentum and other simple rules to affect what happens in the game. Prom Week, developed by Josh McCoy and colleagues at the University of California, Santa Cruz, uses social interactions to drive the game in a similar way.

These include multilevelled social networks that determine whether characters are friends, dating, or are enemies. There are also rules about feelings, such as a secret dislike for another character. The characters have distinct personality traits – they may be competitive or witty, for example, and have a shared social history and knowledge. The game tracks previous interactions and the status of common objects, so calculators might be lame, while footballs are cool.

Each level in Prom Week focuses on a particular character with a number of goals, though the player can control any of the characters. Selecting two characters brings up a list of potential interactions such as giving advice, insulting or flirting – the available options are determined by Comme il Faut’s social rules.

Prom Week‘s style of storytelling is more natural than The Sims, in which characters communicate using icons and nonsense-babbling. Prom Week characters speak in text-based English, thanks to dialogue templates for around 1000 scenarios based on characters’ relationships: particular details are filled in using past experiences or personality traits.

Prom Week was released as a Facebook game last month but Comme il Faut is also available separately for others to use in their own games. “We’re hoping it will raise the bar on storytelling and video games,” says McCoy.

Daniel Kudenko, who researches artificial intelligence for games at the University of York, UK, says the high level of detail in the simulation might make it hard for players to predict how characters will react. “You might have a very smart game AI, but if the player cannot understand it, they might think it is stupid.”