Why not? All our characters are expert programmers? Just because I don't duplicate the source code character-for-character doesn't mean that I can't get the same effect. There are, after all, many different programming languages, formatting conventions, etc.
So, once someone creates a spell for a ball of fire that flies out and blows up, no one else can ever make a spell that has a ball of fire that flies out and blows up? Or does that mean that I can't call mine "Fireball", it has to be called "Indirik's Spherical Conflagration"? Or perhaps mine has to have blue fire, instead of orange fire? Or it's made of hot plasma instead of burning fire?
I'm not trying to be argumentative, here. I'm just trying to get a better understanding of the system. It seems to me that if once the generic spells have been designed, that creating new ones will get more and more difficult. So the people that start first, and especially the ones that "register" all the common spells, will have a huge advantage over the people that start later.
Theoretically, you can invent spells, duplicating other people's effects. We may have a library of "common spells" that can be learned that way.
Like complex software, artwork, constructions, inventing one from scratch is very time-consuming. Yes, you can re-invent the combustion engine or the lightbulb without ever having seen a blueprint - but it will take years of failed experiments, getting the proper resources, fiddling with the details, etc. etc.
That is why we won't simulate the re-invention part within the game. It would mean dedicating your character to this task for a very, very long time.
