You case it's more like the case of copyright. But there is not enough only pure "idea", i mean something like "oh, i want to create galactic chess please copyright it for me" or something. You should create it a first, show that this is work and when try to use copyright.
This was one of the first things that I asked in this thread and I never got an answer, having an idea is not enough to get any kind of copyright or protection for your rights, you need to actually develop the software and the idea to the point that you can bring something to the table, and at least to me it does not seem as if the OP has done anything to deserve a copyright protection and if that is the case then it is a mistake to try to bring that idea to the casinos as they are not going to take you seriously.
That is what copyright to be applied needs, the platform should have a working product because having just an idea to be patented is worthless, even patents will not accept it. First, we need to establish the code, test the game, launch it in the internet by having a domain, let people know about it, and lastly, make sure that we aren't using any public characters from other people's work, nor using any effects, soundtrack that is owned by anyone else. In short, every piece of our ideas and implementations should be original. But as far as I can see, most of the gambling sites have these games where the game's color and the theme is strictly aligned to the overall design of the gambling site. This way, even if the game isn't patented, it is hard to just copy the game.
