The mode, Eliminator, will be added for free in the racer’s Series 17 update on December 12.
“The Eliminator invites up to 72 players to face-off within an arena set in the open world of Britain,” the developer said on Wednesday.
“Eliminating one another in head-to-head races to earn upgrades and a chance to pick up faster cars. Arena walls contract throughout the game, forcing players closer together until a final white-knuckle race among the survivors determines the winner.”
The new mode follows Forza Horizon 4’s paid-for Lego expansion which was released in June.
The game’s Series 16 update added new cars, a new Showcase Remix, Auction House Improvements and more in November.
The core Forza series developer Turn 10 said in June that it has shifted “focus away from Forza Motorsport 7 and towards [its] next project”.
The studio has released a new Forza Motorsport instalment every two years since 2005, the last being 2017’s Forza Motorsport 7, but franchise creative director Dan Greenawalt admitted that with regards to a release window for an upcoming sequel, “we don’t have one”.