Xbox One exclusive Forza Motorsport 5 is free to download this weekend for all Xbox Live Gold subscribers.
Microsoft has said the game will be available without charge from 12.01am PDT (8.01am UK time) today in all territories, until midnight on Sunday.
We had a quick look ourselves and couldn't see the deal live yet in the UK - let us know if you spot it and we'll update.
Microsoft has said that it is the full version of Forza 5 on offer, not a trial, and that Achievements unlocked will remain after the game's free availability period has ended.
The offer is similar to a limited-time free game unlock option for Max: The Curse of Brotherhood that was spotted by some Xbox One users last month.
At the time, Microsoft said that the offer had been posted "in error" and that more information on similar promotions would be announced in due course.