I was skeptical when I came across a Reddit poster claiming that they “definitely” encountered a cheater in the ranked Rocket League. Uh huh, just like everyone who kills me in Rainbow Six Siege is “definitely” aiming, right? Then I watched the video.
Friends, I am sorry to inform you that people cheat in Rocket League.
The alleged cheater was actually on the same team as ghost_snyped, the Reddit user who posted the video (opens in new tab) Embedded above, showing the cheater’s perspective for part of a doubles game. I’ve been playing Rocket League for seven years and I’ve never seen a human being play like this at any rank. There are masterful Rocket League dribblers, but it would be unusual for a skilled player to remain so rooted to the pitch – most throw in some aerial maneuvers here and there – and to carry and shoot the ball. Which flawless. Sure, this is a real problem: people have started using a machine learning-trained Rocket League bot in online matches.
The creators of RL Gym (opens in new tab), an API that allows training Rocket League bots with machine learning algorithms, knew their project could be used by cheaters, but that was not their intention. There’s actually a cool non-cheaty Rocket League bot development scene centered around another API called RLBot (opens in new tab)which allows custom bots to be created and used to play offline or compete against each other in LAN tournaments.
RLGym changed the game by allowing bot developers to use Rocket League as an environment reinforcement learning (opens in new tab) algorithms. The basic idea is that instead of scripting your bot’s behavior by hand, you tell the system what outcomes are desirable – the ball getting closer to the opponent’s goal, for example – and then run hours and hours of simulated Rocket League in which the bot gradually “learns” to achieve those desired results.
In practice, it’s not nearly as simple: “Designing reward functions is an art in itself,” said one of RLGym’s authors, Aech, who ran a question and answer on Reddit (opens in new tab) about the cheating problem last week. The specific machine learning bot used to cheat in Rocket League, Nexto, was created by the RLGym team and was “exceptionally difficult to make,” Aech said. That makes it unlikely that tons of Nexto variants will pop up, but now that cheaters have caught on, Aech expects someone to train an even better bot using the RLGym API.
So the bots themselves are not new. What’s new is that someone has implemented “their own tools for manipulation”. [Rocket League] which don’t have the same restrictions against online play as RLGym and RLBot,” says Aech. That’s why Nexto now appears in ranked matches, something RLGym doesn’t approve of.
“RLGym is incredibly lucky to have found a super passionate and understanding community, and we’re not going to let these cheaters hold us back,” Aech told PC Gamer. “We are taking steps to ensure that our bots cannot be abused in the future and we can’t wait to show everyone the exciting projects we have been working on.”
I’ve emailed Rocket League developer Psyonix for comment and will update this story if I hear back. The studio has not made a public statement about Nexto’s cheating issue at this time.
It’s not clear at this point if we’re looking at a Nexto epidemic or just a handful of incidents, but I’ve seen a few other popular Reddit posts complaining about encounters with the bot in ranked matches. The other clips show alleged cheaters playing with the same extremely demanding ball handling.
For now, there’s nothing a player can do when matched against a suspected Nexto bot, other than report the cheater and do their best to beat the machine. If you need a tip, apparently it’s not very good at face-offs due to an emerging mistake in training.
“A rather curious phenomenon that we have seen repeated by several people [machine learning] projects now is that bots typically learn early in training how to be really good at kickoff, but as they get better at the rest of the game, they almost always seem to lose that ability to do good at kickoff,” wrote auch.
It really feels like the kind of flaw a protagonist in a sci-fi movie would discover right before their final confrontation with a rogue AI.
At the end of last year, I said that machine learning represents a real change in the way we interact with and understand computers, and here’s another example. As a hobby research project, RLGym and Nexto are super cool. Along with experiments like Google’s StarCraft 2 AI, these Rocket League bots predict a future where games will feature much more capable and potentially lifelike AI opponents (though Nexto’s playstyle is rather brutal). At the same time, we’re now dealing with the most sophisticated method of cheating ever: bots that can theoretically be trained to master any game, perhaps even mimicking occasional human error to be hard to detect. It’s going to be a wild decade.