Get access to builds of the game when they're released, earlier than the public does.
You get access to test builds and will have your name in the credits.
You get access to devbuilds at any time (which may or may not be broken), your name in a special section of the credits, and (optionally) on our website for everyone to see. You also have the right to design a quest or character in the game.
You get your name in an even more special section of the credits and website, are allowed to view the game's source code, and can design a playable character or major questline.
You get personal input into the development process, and can request major additions (features, storylines, etc). You also get your name proudly featured anywhere it'll fit.