Copy protection

What do you mean by safe? If you mean itll stop people copying your game then not very. People could rip your game and put the Key in with it, or write a keygen. Using key methods you can stop two people with the same key playing the game at the same time (although if two people come on with the same key what do you do? what if one of the people bought the game legitimatly? some of the problems you have;) ).

If two were playing with the same key I would kick them out of the game and delete the key and generate a new one and send to the buyers email and he would have to update his key. And if this happens more then 3 times his account would be erased. I plan on distributing the game for free but you'll need to buy a key to play it.

I'm assuming you use a name/password mechanism for authenticating the user, storing game history and stats, doing match-making etc.

Why do you need the key at all? If you need to be online, I would suggest just charging for the login account needed to play -- the "key" is the login account name and password; no key needed.

The question of "safety" varies by what the game does. If the game is good, and you provide poor support, and it's peer-to-peer (such that the login information is mostly extraneous and for protection only), then users will likely hack the game to make it "log in" to some free server that accepts any key/username.

If the game is bad, or you provide great support that's worth the price of payment, or it actually requires the server to play for intrinsic, game-design reasons, then the risk of others patching your game to steal it is less.

However, I wouldn't worry about hacking much at all. Make sure your game is fun, that you listen to your customers, that you provide excellent value for money (including support), and your biggest problem will likely be figuring out how to deal with all the players who will flock to you. Assuming you can figure out how to market it first, of course ;-)

Thanks for the pointers hplus.