As we all know in this day and age a lot of ideas and concepts are taken from elsewhere, or influenced/inspired by something else. The question is how far do you think an idea can go before it can be considered a rip or bluntly stolen? The reason I ask was, in dao I liked the concept of the blood mage, but I feel they didn’t do the blood mage justice in the series. I wanted to come up with my own story and lore for blood mages and a story following a blood mage (It will involve using blood, rituals, and demons), but with dao large fan basis I did not want to be looked at as someone simply stealing a concept and trying to call it my own.

If you only take the name, you are not making anything wrong. For example in runaways the writter take the concept of Giborians (Giborins) who means like the powerfull (like some kind of hero) to create half Gods who are going to destroy the world.

But all this depend also in your references and how you use it. For example if you create blood elfs but you make it live in the same world as WOW, then is more like a you making this world look like you want (and you are raping the reference). But if you create another world with their own mythology and characters and use the therm of Blood elf, I think there is no problem.

I am mostly creating my own world and more mythology, but I am a old fantasy type writer with demons and deities. Dao follows alone those same lines, while about 50% of the lore I do not like. I'll still be walking the thin line in fantasy with the idea. A few things I do know that I can do is not put things like templars that hunt mages in the story, but the summoning and contracting demons is something I would have to do, just because I love those forms of magic. I could make it that he is the starter of blood magic which can..... ok nevermind scratch that.

think about this. Tolkien creat elf, Dungeon & Dragons took the elfs and did their versions, and WOW did that to, and other did that. And no one care, because everyone creat a different mythology and world.

If the world is yours, then go for it (but of course it will have in part, some of the tolkiens ideas).

PS: even more, elf were created be tolkien as a interpretation of a mytologic elf.

Tolkien has always inspired me greatly. It is just seems harder to try and create something without ripping something off, but silly goose guess I will get to work on it.

ideas are pretty much circulated now so coming up with something completely original might be hard without spewing the contents of you brain all over the place and gathering up whatever you can to make an idea...anyway, taking an already established concept is fine, just twist it up and make it your own, that's what I say.

Using WoW as an example of what is not plagiarism is a very bad idea. WoW is almost entirely devoid of original thought. Nearly every single thing in that game is stolen from Warhammer or D&D. There's a bit of innovation here and there, sure, but when it comes to illustrating the difference between being inspired by something and being a nigh-plagiaristic rip-off, WoW is firmly in the latter end of that spectrum.

The relationship between the first Starcraft (but dear god not the new one) and Warhammer 40k/Aliens/OtherSF is a good example of being inspired by something while still being original and not derivative.

A little ironic, when you consider how much Warhammer Online later ripped off WoW - though admittedly not from the worldbuilding side of things - just everywhere else But that is besides the point here.

It's impossible to ever completely avoid 'omg you stole' or 'this is exactly like' comments, I'm afraid. People love to compare things and find similarities - and, more annoyingly, point them out. What I mean is, I wouldn't recommend omitting any of the details you really like about blood mages because some chucklehead calls you out on it.

If you take something like Harry Potter, you can think that wizards with wands who ride broomsticks isn't a particularly original idea. And some of the names aren't original, Sirius and Bellatrix being stars. It's your own personal details that make things original IMO