What is your statute of limitations on marketing one's own version or copy of an existing magic trick?
Should the re-creator be given one year before the door is opened? Five years? Fifty? Never?
Is "Imitation the sincerest form of flattery?"
Without naming names or bashing, what is the philosophical basis for your perspective?

How about asking their permission?

That makes sense.

Copy is one thing, one's own version is another.

If it is a standard routine, and you have your own routine/presentation/version....go for it.

There are also other ways of acquiring the rights to produce a certain effect.

Blair

So it's okay to publish the how-to of your tricks as long as using a different colored card back and maybe using a different tagline/callback for the jokes?

Hey when I saw you do those tricks you were wearing a blue tie - I'm wearing a red tie for my version so what's the problem. And check it out- green socks here so don't give me any of that copying nonsense.

And what's it to you if I put my version on YouTube so everyone can enjoy my tricks?

So Jonathan, just how different does an effect have to be before one can fairly publish or market it?

Here's my perspective:

If you want to expose - go ahead and publish into our open market. If you are making a work available to all and sundry via any open market - you are exposing. If you want to teach - let students find you

If you really believe you have original work (vetted) that's based upon others work - just cite the originals and explain where your findings fit in the scheme of things.

And of course scripts and design work on classic items in print are likely welcome and can be shared without need of exposing anyone else's work.