New Delhi, July 17 -- the characters she wants, the kind of world she imagines, the way the game should work. Within moments, something playable comes back. That is the premise of Build, Roblox's new AI-powered game creation tool, which the company announced this week alongside a public alpha launch date of July 28 for New Zealand users. It requires no coding, no 3D modeling experience, and no knowledge of how game engines actually function. Describe the game you want, and Build assembles it.

users younger than 16 can share their creations with friends, but only those 16 or older can publish games to Roblox's global platform, where millions of players would discover and play them. The restriction reflects a tension at the core of Roblox'...