I'm probably the last person who should be giving advice in this thread, given my experiences with relationships are rather pathetic. But I learned a long time ago that you can't force someone to be what you want them to be, you have accept who they are. It was a very difficult lesson to learn, and sometimes I wonder if I ever really recovered from it, but I also believe it was probably one of the most important lessons I ever learned in my life.
Maybe this relationship is one that can't work, I don't know and can't really say. But I think in not being able to accept something that is part of a person's life, then to some extent you're rejecting that person. Women say that they don't want to give up their individuality for a husband; maintaining a certain amount of personal independance is a huge goal for women who embrace feminist ideals. For quite some time, I kind of resented some of that philosophy out of immaturity. Then I realized I wasn't so different, what I want from a wife isn't really that different. I want, no need, someone who accepts who I am instead of seeing me as some tame ape that needs to be housebroken as she sees fit. And I need to be able to do the same thing in return. I'd rather stay single and miserable and at least enjoy things I like than be married, not be able to enjoy things I like while being pressured to endure things I can't stand, and still be miserable.
Besides, it's not that much of a sacrifice to let the person have some independance, as long as that independace doesn't involve something that threatens the relationship itself. For me, that would be something like infidelity or even spending time with friends who are very openly hostile towards me, or demand their friendhip be more important that the relationship. That's not a matter of forcing her away from her friends. It's more like I don't accept the notion of "bros before hos"; and I want her to feel the same way in return.
There is no real truth to that saying "opposites attract". Think about it.
On the other hand, if your partner is basically a carbon-copy of you, liking all the things you like, then your partnership doesn't enrich either of you very much. Might as well date yourself.
I think the reality is in the middle somewhere. There needs to be some similarities for a relationship to work. Some differences will not be good for a relationship. Religion is a big one; many religions are just not compatible, and it's not going to work if you think your partner's beliefs are nothing but wickedness. There's no way around it either; after the initial heady romance dies, you'll feel resentful that your partner doesn't share your faith. Then children just make things worse, because both of you will end up fighting over exposing them to each other's beliefs. Politics is another big doozy, though it might work a little better if you agree to keep it out of the marriage. Just be careful when Junior or Princess hits those teen years, discovers activism, and starts dragging all the politics into the home that you both agreed to keep out for the sake of harmony (having a talk together with the kid and explaining that the home is supposed to be neutral and you expect it to stay that way might help).
But you do need some opposites. It helps to make both people more rounded, and it might introduce you to new interests.
I think saying date only women who like RPGs is a bit restricting. I think better overall would be to stick with women who are into nerd culture is a better approach. It's broaders, and even if she doesn't like RPGs, she still shares a lot of common interests. For me, dating a mundane seems pointless because I want to share my interests with someone else. What good is it if she just doesn't get RPGs or video games, or all the nerdy franchises I like, while I'm completely and utterly bored with what she likes, and have difficulty hiding my contempt for them? That might not be the right approach for the OP of course, but at the very least, there needs to be enough sustained interests so that as you grow older and change, you change together, rather than growing apart.
For two people who are very much in love with themselves, this could be a great solution!
The only marriage that would satify a narcissist is one that involves a mirror.