First of all I'm not a big fan of Percy Jackson series and have never read the books and only seen some of the first movie, but I'm very interested in mythology and stuff like that and am just coming up with an idea in my mind about something that I guess could be considered similar to the Percy Jackson series from what I seen of the first movie and movie previews. Instead of a book series about Ancient Greek mythology being real I have an idea for a possible series of books about Norse mythology being real, well sort of. The gods and goddesses of Norse mythology were actually advanced human like aliens who knew about magic and who came to earth long ago to help with it's creation. The story begins with with two distant cousins about the same age one who's a teenage boy and another who's a teenage girl (haven't thought of names yet). The two aren't even aware that they are cousins in the beginning until they are told so by a family member that they are cousins and that they are distant descendants of the Norse “god” Odin and that there is a secret group led by a mysterious masked man who wants to get rid of all those who are descendants of the Norse “god” Odin because of their power. I got this idea while watching ancient aliens on history channel last night so it's a new idea and I need to do more research on Norse mythology. Anyway is this too much like the Percy Jackson series.
Actually this somewhat reminds me of Marvel's Thor, in which the Asgardians were actually aliens who never claimed to be gods, but rather were assumed to be by people long ago. Even in the movie, Thor states that magic is just science we don't understand yet. I don't think Marvel's Asgardians had a hand in creation though. And as far as a plot with a teenage boy and girl who turn out to be cousins, no, that isn't like Percy Jackson. Percy and Annabeth in that book are both descendants of Poseidon and Athena respectively. Other than that, I don't know if there's any real similarities. I haven't actually read the book. I've only watched the movie.
Keep away from making a camp for teen demi-gods with abilities do to a parent being a god and you should be safe from being too similar to the Jackson series. (Which I'm a HUGE fan of by the way.
Okay I didn't really realize it was too much like marvels Thor. I knew marvels Thor is loosely based on Norse mythology but having not watched the movies or anything didn't realize I was kind of stealing the idea. Seriously it's all coincidence how much my idea is like marvels Thor.
writers have been writing updates on every mythology ever dreamt up and new stories based on same for as long as myths have existed, so stop worrying about what's been done, just go ahead and write yours! even if starting from the same story premise, no two writers will come up with the same plot, or wording, so as long as you're not appropriating newly made-up characters from published works, you'll be safe... that said, keep in mind that marvel and disney, for two major examples, are extremely protective of their characters and stories, so be sure you're not going over that line...
Yeah I'm really nervous about this being too much like marvels Thor but with my own characters in it and Disney getting on me if I ever get this idea out. But at the same time I am really into this idea at the moment. I could make the main focus on the cousins and how they have to find others who are descendant of the Norse gods and goddesse and them having to fight this group of people led by a masked man who is jealous of their power rather then the gods and goddesses themselves besides I'm thinking that the Norse god Odin is actually a distant ancestor of the cousins. I don't know if that would be good enough though.
I actually thought about doing something like this earlier this year. And I had the same question. I'm not telling you not to do it but, just be forewarned, Rick Riordan is writing a Norse Mythology series that is due out in 2015.
which may just kick off a new fad in fantasy, making it easier for new writers to get their norse myth-based work looked at... so i don't see that as a drawback for the op at all... more like a golden opportunity!