I was wondering what it takes to sell a mod. Is this possible, do you have to buy rights from the developers? And how did counterstrike come to be, was it a bunch of rogue modders having fun or were they hired on by valve? Any help is appreciated.

1) You generally can''t sell a mod. The company that wrote the original game can with your permission, though. You would get a percentage (maybe even a large one).

2) Counterstrike was a couple of guys writing a mod for fun. Valve bought it from them and hired them (or some of them, I forget) to work at valve.

Check the licence agreement with your software. If it was written in the last 5-8 years it will almost certainly have something about what you can and can''t do with mods (which is usually that you can''t sell). If you can''t understand the lawyer speak, paste that section here.

CounterStrike was just another (popular) mod until Valve approached them. Valve basically bought the rights to CS as far as I know at that point. The developers continue making it with additional support from Valve. They may have hired one or two of the developers on full time. Eventually, Valve decided to take it commercial.

Generally, you can approach the original developers or the publisher (depending on who owns the ip), but unless you have something really stellar to show, you probably won''t get much attention.

If you spend a lot of time and effort on it, and have something to show you are serious and can pull something off, then they will be much more willing to listen (hence Gunman Chronicles).