When registering, "gender" is a compulsory option, and you can only choose "male" or "female".
It would be good to add an "other" option if you do definitely need to record gender for some reason, since there are people whose gender doesn't fit into "male" or "female".
If you're recording gender so that you can use specific pronouns (eg "his" vs "hers"), maybe you could just ask for that rather than gender; and again, there are people who don't use either. Sites like Facebook let you choose from "she/her", "he/his", "they/their" eg "andc played 3 copper on their turn and they bought a silver".
:)
I would actually prefer if one could do away with he/she, his/her and stick to they/their.
I like having genders showing just for the sake of more accurately talking about opponents, but I think it should be an optional choice (male, female, other) and should default to "they" if no choice is made.
As per the release later today (0.12.12), you no longer choose the gender at sign up but a possessive determiner, with the choices being "his", "her" and "their". When we import the usernames we will get from Making Fun, we will default to "their", with users being able to change it as they see fit.