AI bots can beat humans in multiplayer game

Researchers have developed an artificial intelligence-enabled machine that can beat human players in a tricky online multiplayer game where player roles and motives are kept secret, says a study.

It was presented at International Conference on Information Systems.

The machine called "DeepRole" is the first gaming bot that can win online multiplayer games in which the participants' team allegiances are initially unclear, according the study from Massachusetts Institute of Technology (MIT), US.

The bot is designed with novel "deductive reasoning" added into an AI algorithm  commonly used for playing poker.

This helps it reason about partially observable actions, to determine the probability that a given player is a teammate or opponent. In doing so, it quickly learns whom to ally with and which actions to take to ensure its team's victory.

"If you replace a human teammate with a bot, you can expect a higher win rate for your team. Bots are better partners," said study first author Jack Serrino from MIT.

The researchers pitted DeepRole against human players in more than 4,000 rounds of the online game "The Resistance: Avalon." In this game, players try to deduce their peers' secret roles as the game progresses, while simultaneously hiding their own roles.

As both a teammate and an opponent, DeepRole consistently outperformed human players.

"Humans learn from and cooperate with others, and that enables us to achieve together things that none of us can achieve alone," said study co-author Max Kleiman-Weiner.

"Games like 'Avalon' better mimic the dynamic social settings humans experience in everyday life. You have to figure out who's on your team and will work with you, whether it's your first day of kindergarten or another day in your office," Kleiman-Weiners said.

The bot is trained by playing against itself as both resistance and spy. When playing an online game, it uses its game tree to estimate what each player is going to do.