The goal is to rotate the cap without moving the bottle itself. And everyone is trying it. Like most challenges that catch fire online, this one doesn’t require much to participate. All you need is a bottle, a cap, a camera and plenty of time to hone a skill that, while not exactly useful, is highly entertaining. Of course funnyman Ryan Reynolds tried it... and it didn't go according to plan. But, it's a great plug for his gin! lol