I know lots of gamer girls and its only through doing things like going to a starcraft or call of duty night at a local shop
In any case, if you want to meet a gamer girl, go find gaming groups in and around your town and skip the website business. Or playing Magic: The Gathering down town with some people i’ve never met before, or (insert whatever game styles you like here.) applies to pretty much anything. I am like you in that I want a partner who I can game with ect. I do not believe that looking for someone who is into the same things as I am is really “basing my life off of gaming” as an above poster said. I am not a hardcore gamer, i play games reasonably often but i dont go nuts, I still go outside, i still go to parties and I socialize. But i’ve been there and done that with women who do not entirely share the same interests, and it sucks because some just dont really “get it”. And nothing beats firing up a co-op game with your significant other and both enjoying it equally rather than her just having to “accept it”.
Why settle for someone who just accepts things when you can be much happier with someone who you can share it with instead? Nothing wrong with being picky, I certainly am and I do just fine.
Seriously, answer questions and perfect your profile and you’ll be most of the way there. Don’t limit yourself, but know what you want. You may be surprised.
And to echo: find a local game store or group and make friends. The classic approach isn’t dead yet, especially for people with less-mainstream hobbies.
Granted, I also changed my style of dress and gained a fuckload of confidence, but OKC made it much easier for me to meet interesting dates.
I’ll echo the statements of your original line is pretty narrow and a bit shallow. Most of my friends who are gamers have non-gamer girlfriends who either tolerate their gaming habits or have started picking up on them to enjoy the same hobby.
That said, I know I was in a similar position a while back and one thing that I realized now was that most gamer girls are not generally on dating websites
You need to go out and do activities that they would likely be a part of, even ones that you might not generally take up on your own. I’m not sure 
where you live but I would start looking for conventions that are in your area. I live in Omaha, Nebraska and went to a very small con held here but the ratio of men to women was as close to 50-50 as I have ever seen for being classified as a nerd activity. Incidentally I was attending the convention with a friend who became my current girlfriend. I’m not saying that there will be a sea of single women but it is a starting point.
Like I said, I’m not going to turn down someone because they aren’t a gamer girl. But I don’t think I’m being too picky by looking for someone who will do more than just tolerate my hobby. It’s been a sore point before with a girlfriend who had this secret expectation that I would drastically cut back or stop playing games after seeing each other for a few months. So it eventually became an issue with her when it was clear that I wasn’t going to change. Something along the lines of “Why would you go to Boston to play games for 4 days that weekend? You need to be my date at a friend’s wedding (that I don’t know, and she hasn’t seen or talked to in years). How could you do this to me. “