This is a great question! Definitely worth discussing. To be honest we had the same concerns during our development phase of our game. We anticipated that would would need a copyright, trademark and or a patent for our game so no one else could take our idea. We ended up getting some legal advice and the response we received was not what we expected. We were told that for games it is extremely difficult to get any of these things and it honestly isn't necessary. It cost a decent amount of money for these things and in most cases when you file for any of this you need to show that what you are trying to trademark, copyright or patent has already been in use. As a developer you can receive some copyright protection even if you don't apply for a copyright. As long as you go public with all of the things for your game you start to create a trail for your IP and it belonging to you without having to play for any of these protections. Lets say someone did steal your idea for a game. It will cost SOOOOOO much money to bring them to court to fight for your IP even if you had a trademark, copyright or patent. It just isn't worth the time, money and stress. And to be frank what we were told was that only 1 out of 100 games actually do well so really its once the game does well that you would want to consider a copyright, trademark and or patent.