In formal English the default grammatical rule is that the masculine pronoun serves as both specifically masculine and as default generic neutral, and that feminine pronouns are used only when the subject is unambiguously female (e.g. if it's been established that one is talking about biological mothers). Recent decades have seen a protest against this by claiming that because female readers don't see female pronouns in contexts where the subject could be either sex, the cumulative subliminal effect is to convey a message of exclusion -- if, for example, an otherwise-undescribed player character is only ever referred to as "he", it is claimed that the inevitable inference will be that all player characters are male.
I think that in part the desire to use the feminine pronoun as the default neutral is an attempt to prove this effect to male readers -- and to be honest, I do sort of see it myself, despite being a thorough skeptic of the Sapir-Whorf hypothesis of which this is an offshoot. Part of the reason I was unable to get through the recent SF novel Ancillary Justice, by Ann Leckie, was that her protagonist and narrator is established as speaking a language which has no gender pronouns, and for which (for some reason) the in-universe English translation convention is to use the feminine as the default. As a result, every time I tried to read the book, I kept tripping up on the fact the protagonist/narrator identifies every other character encountered as "she" or "her" in ways that I knew would not always be accurate, and so I got stuck every time trying to figure out if this character actually was female or not. Ultimately, I was never able to get through more than a chapter or two of the novel, both because I found this a fundamental block to understanding the story, but also because I simply could not shake off the feeling that the author was trying to say, "See, this is what it feels like when the 'generic default' of a language excludes you," and however important that lesson may be considered, I don't want to fight through it every chapter to enjoy a novel-length story.
For games, I find the best approach is, wherever possible, either to name example players and characters first ("Craig, and his character Sam"), or to write in second-person directly to the reader ("If you buy this Power, your PC can fly"). Do this often enough so that the reader isn't drowned in generic neutral "he"s and most sane readers will generally not complain.