[Borealid]

Let's say I come up with the idea of using a fan to blow a balloon into the air. I get a patent with the claim "a device made buoyant in air and propelled by forced wind".

Someone else comes up with the idea of blowing a dust bunny into the air with their breath.

Their idea, which has nothing at all to do with my idea and is certainly not a copy, infringes my claim because what they are doing matches what I've claimed as the core idea in my patent. They didn't "copy" me, for two reasons:

1. Their idea was had independently of mine, with its own creativity 2. Their idea is fundamentally not the same as mine, but because my enumerated claim is sufficiently broad to cover their concept too, it's still infringement

With a copyright, their additional creativity would have made their work not infringe. With a copyright, you can't claim anything broader than the work you actually produced.

[bonoboTP]

> With a copyright, their additional creativity would have made their work not infringe.

But not generally. You can't sell a new Hogwarts-based book with Harry Potter characters. This is both due to copyright and trademarks. But already copyright blocks derivative works even if there's additional creativity with a new plot.

[Borealid]

You can't sell a Harry Potter book, but you can sell any number of Magical School for Wizards books. They can use similar themes to Harry Potter, similar pacing, even similar artwork styles.

They just can't copy the characters, significant chunks of text, or images.

That's the difference between a copyright and a patent in a nutshell: you copyright an implementation of an idea, while you patent the idea itself.