In 1973, the performer Hugo Zacchini sued Scripps‐Howard Broadcasting after one of its news programs aired his entire act on television — an act in which he shot himself out of a cannon at an Ohio county fair and landed in a net 200 feet away.

The case made it all the way to the Supreme Court, which found in his favor, saying, essentially, that if someone could watch the whole thing on television, why would they bother to get off the couch and see it in person?

Today, a new set of cases is nudging the legal boundaries of who controls certain performances. This dispute centers on dancing avatars in Fortnite Battle Royale, one of the biggest video games in the world, and whether the moves they do are owned by somebody else.

Three performers have sued Epic Games, which makes Fortnite, an addictive, money-minting juggernaut of a survival game where players fight it out to stay alive while they kill everybody else. The game is free to download, but players purchase add-ons as they go along, including a rotating offering of dance moves called “emotes.”