Competent AI opponents are the key to a good single-player racing game. And with this week’s update, Gran Turismo 7 is getting an AI upgrade as Sony rolls out its Sophy AI agent as a permanent feature of the game. The entertainment company tested the waters earlier this year for a few weeks in a limited test, but when the GT7 Spec II update rolls out to consoles tomorrow morning, Sophy will be able to race 340 of the game’s cars on nine of its tracks.
Ideally, you want the AI in a racing game to be good enough that the race is a challenge, but perhaps not quite so unbeatable that it’s a fool’s errand to try to win.
That’s been harder than it sounds to get right—the older players among us will remember the AI in earlier installments of GT, which mostly stuck to a preprogrammed line with little concern for where you, the human player, wanted to put your car. Microsoft’s long-running Forza franchise actually has its origin in a neural net experiment, and more recently, its developers used each human player to train an AI agent that would populate their friends’ games, albeit with imperfect results.
Sony AI introduced Sophy to the world in 2022, publishing a paper in the journal Nature explaining how the company trained the AI to be able to beat the very best human GT players in the world. In late February of this year, a time-limited feature added a series of four-versus-one matches against Sophy set to different difficulty levels, as well as a match where the AI is completely unleashed—and almost completely unbeatable, at least to us mortal players.
“One of the of the challenges that really sticks out was trying to find a good balance between having the Sophy car be respectful of opponents around it—so have good sportsmanship—but at the same time being competitive in a race and making sure that it tries to take advantage of positions,” explained Kaushik Subramanian, senior research scientist at Sony AI.
“Finding that gap is the fine line,” Subramanian told Ars. “Because you don’t want to be overly aggressive. You might be trying to be overly aggressive to gain that position but at the cost of very poor racing ettiquete. And our team has gone back and forth trying to find a way to walk that line because (a) that line is not clearly defined, and (b) people have different interpretations of that line. I might look at a race and say this was like this, but [Polyphony Digital, the game developer] or somebody else might have different interpretations.”
It’s not quite as simple as just replacing the old in-game AI with instances of Sophy, however; you’ll only be able to race Sophy in the Quick Race mode (née Arcade mode).
“The technology allows us to run 20 cars at the same time, so that’s a limitation,” said Peter Wurman, director at Sony AI. “In the past, we had a policy that could drive one car or small set of cars, like in the race together last February. And that’s not scalable—like one car at a time across all the track combinations. So we’ve been working to make policies that can drive many, many cars.”
“The research goal is to get an agent to the point where it can completely replace the built-in AI and make the racing experience much more realistic and much more enjoyable for all players of all types. The current setup is mostly ‘chase the rabbit’ scenarios, and you have to go online and race humans to get a real racing situation, but that’s also its own complicated mess. If you could do that by yourself with the AI that’s in the game, it would be a lot more fun, I think,” Wurman told Ars.
The update also adds seven new cars (including the Lexus LFA, Mercedes-Benz 190E 2.5-16 Evo II, the latest Porsche 911 GT3 RS, and the Tesla Model 3), a new snow track with three layouts, some extra events to complete, including 50 new license tests, and four-player split-screen races (only on the PS5).