Unless you are actually applying to a company in the video game industry, I would highly recommend that you avoid trying to use this as legitimate bullet point on your resume. In my experience, unless a person is a game player themselves, it is very difficult to see the value in such a potion, or organization skill required to maintain it. In fact, a great deal of people might see it in a bad light, which of course is the opposite of the intended effect.

That said, if you are certain that you want to go this route, make sure you mention it only briefly, and couch the experience in terms that are a bit more obtuse than you would otherwise. For example, instead of saying your position was for a guild in EVE, state that it was a leadership role in a 2500+ strong online community. Emphasize the elements of the position that directly relate to the skills that a prospective employer would hire you for. Most importantly, keep it short, very short. It should be the icing on the cake for an employer, almost an afterthought, something that solidifies their interest in you. And if you find yourself in a place where you need to explain the position further, don't start gushing about the gameplay aspect of it, stay steady and calm and direct any conversation about it towards the importance of the role and the responsibility and trust you carried while you held it.