The 1987 West and Zimmerman article 'Doing gender' argues that throughout our daily lives, we are always 'doing gender', reinforcing what is acceptable behaviour for females and males according to socially defined gender roles. Through the examination of a qualitative study, this article explores the relationship between 'doing gender' and 'playing gender' in online virtual worlds, comparing differences in the conception and performance of gender in Second Life, primarily a social world, and Guild Wars, primarily a role-playing game. It also explores players' perceptions of their own avatar gender choices, gendered play styles more broadly, as well as perceptions of in-game gender ratios.