In response to John Brown
John Brown- Well done on an interesting alternative insight and different thread of arguments to those already proposed. However, I do feel that there are inherent contradictions in your argument. Moreover, it stands clearly at odds with fusangite's argument in some areas.
As far as the caveat of: “but what if they are mature, responsible people that have demonstrated that they can play cross-gender roles?”, try this scenario. How would you feel if you were new to a group and didn’t get to play a female character, while others did, and the reason you got for this situation from your new DM was: “You haven’t demonstrated to me that you can role-play a female (or male)?” I don’t know about you, but I would feel pretty insulted by that.
I am not sure whether you are with Kahuna Burger and fusangite with this one, but they have certainly expressed sentiments that it is fine for females to play males but not vice versa. This scenario is a genuinely good argument, but if were to extend the scenario, it would also be insulting to allow females to play cross-gender whilst banning males from doing so.
In addition, the issue of what sex a character has only really has importance if sexuality plays a part in your game. It doesn’t in mine. My dragons don’t care if you are a male or female, they are equal opportunity eaters. Anyone trying to explore their sexuality through my game, is likely to receive a response something along the lines of “The Diamond Cabaret is just across the river, head over there if that is what you are looking for. We’re here to play a game.”
Again, this stands in stark contrast to what has gone before, and indeed implicitly in your own argument. In saying that gender only matters due to sexuality, you must also ban heterosexual players from playing homosexual characters- which has not been discussed. Conversely, homosexual players ought be allowed to play heterosexual characters of the opposite gender.
In any event, gender is more complicated than sexuality. It is fusangite and Kahuna Burger who are keen to assert that men and women have an irreconcilable psychological difference. Whilst I would not go this far, I would certainly argue that in terms of social perception and interaction there is a larger difference between the genders- even without romance in the game, society has accepted stereotypes and roles for each gender, which do impact upon social interaction. Gender only doesn't matter if you play in games where males and females are sociologically and psychologically identical; or in a pure dungeon-hack.
It doesn’t justify you playing a gender-opposite it my game. It is a statement about exploring character concepts without using the gender crutch.
However, nothing in your argument necessarily justifies banning cross-gender concepts. Personally, I go for the premise not to ban anything unless there is clear evidence of gain, rather than the premise of not allowing anything unless there is clear evidence of gain. The only argument raised is the one that some play cross-gender irresponsiby and immaturely, but then they can equally play same-gender irresponsibly and immaturely. You have offered a decent analysis of many arguments, but unfortunately you fair to bring sufficient burden of proof to call for a ban- and furthermore, are clearly at odds with fusangite and Kahuna Burger in your line of approach.