LogFAQs > #902175085

Back when the game was first released, the UI was nearly identical to PUBG's. So were the game rules (how the barrier shrank, for example). It's one thing to copy an idea, it's another thing to copy the execution of the idea, which in some areas Fortnite devs were and are guilty of.

Look at the Hunger Games vs Battle Royale comparisons of old.

Both had similar ideas, but dramatically different executions. For example, the game rules were vastly different. In Hunger Games you did not have a shrinking barrier but rather permanent sectors that would spawn various hazards like poison fog, whereas in BR, you only had a shrinking barrier and neck collars that would explode if they breached said barrier. Despite this and other dramatic differences (like the whole gladiatorial training), the Hunger Games author was frequently accused of "plagiarism". With PUBG vs Fortnite, even the execution was copied, not just the idea. Bonafide plagiarism.