If you’ve already watched the hit Netflix gameshow Floor Is Lava , you know the rules: “Don’t fall in,” host Rutledge Wood warns contestants, as they enter an obstacle course filled with 80,000 gallons of gurgling goop, “because the floor … is … lava!” It’s a goofy grown-up take on a kids’ playtime staple, rebranded for adults as “the hottest game show in history.” Successfully traverse a chamber without falling into the sloshing “lava” below, and teams of three earn points. Fastest team wins a $10,000 prize — and a lava lamp. That’s it. That’s the set-up for Netflix’s Floor Is Lava, which debuted in June and soon topped the streaming service’s list of most-watched shows in the U.S. But if that premise sounds simple, the real star of the show — that aforementioned soupy lava — is anything but. “Look, we put a lot of research and money into trying to figure out what our lava was,” showrunner Anthony Carbone told NPR from Los Angeles. “That’s why we want to keep it our secret.” It’s