Eh, what? Of course you can do that, and of course you don't give up any rights doing that. Why? Because you OWN those rights to begin with, and you aren't making those RIGHTS freely available.scoriae wrote:You can't go and deem something to be freeware, then sell the rights to it. By deeming it freeware, you gave up the rights to it in the first place.
If I owned the rights to game X, and decided to give it away, but then decided that "Hey, I think I'll go back to selling this game", then there is nothing wrong with that, and nothing that could stop me either. The people that got free copies, can still keep those, but, usually you don't necessarily give away DISTRIBUTION-rights along with making things free, which means that any new free copies from the point where I began charging again, would in fact be illegal.
What you might be thinking of, is the Public Domain, which is something entirely different, and doesn't exist everywhere.