Xbox One is getting Roblox, the inventive build-your-own-game online experience. It’s free to download, and it will come with 20 curated levels and modes built by fans.

Console owners can now swell the ranks of 300,000 existing game makers on Roblox, as long as they have an Xbox One.

About 20 Roblox games will be available initially, with a tentative release date of Dec. 3, and more will be added next year. Roblox will appear as an app in the Xbox One Store.

Roblox is a game creation platform on PC, Mac, iOS and Android with 7 million players a month. Next month it comes to Xbox One to take on the likes of Disney Infinity and Project Spark.