Child Focus, a Belgian foundation focused on missing and sexually exploited children, wants to make the internet a safer place for kids. Its latest weapon is a game called OK Groomer, launched on Roblox, that shows children how to spot and evade sexual predators. (“Groomers” are adults who use fake identities to get close to children and manipulate them.) The stages of the game introduce enemies that represent different “grooming” tactics, teaching players how to identify, report and block them. In return, successful players can buy “OK Groomer” skins for their avatars and spread the warning far and wide on Roblox.