Costume play - or cosplay, to the increasing numbers of those in the know - is really a sophisticated version of the fancy dress most people don around Halloween. But unlike the average fancy dress party, cosplay has grown into a cult movement centred around pop culture and science fiction iconography. Gaming and cartoon characters, superheroes, even TV, movie and book characters are all fair game for the enterprising cosplayers. It's become an admirable art form. Most costumes have exacting, almost nerdy attention to detail and are impressively hand crafted by the wearers. Masquerading is a time-honoured practice, but the term cosplay originates at one of the earliest 'cons, namely LA's '84 WorldCon. Throughout the 80s cosplay grew wildly in popularity at anime conventions and comic-cons across Asia, Europe and North America. By the turn of the millenium, cosplaying was going mainstream. Tracing the history of cosplay, Yahoo writer Adam K. Raymond cites a 1996 episode of Friends as an indication that the niche practice was starting to trend: Who can forget the one where Ross confesses his fantasy of Princess Leia in the gold bikini? This particular image holds its own today, inspiring one of the sexiest female costumes. Revealing bikinis and flashy colours are a recurring theme amongst most of the hottest cosplayers. It's impossible to trace exactly when the transition from nerd to hot happened in the cosplay community but these days, any 'Con worth its salt is guaranteed to have a few seriously gorgeous women parading around in flesh-baring fantasy costumes. The following twenty women are some of the sexiest and most active on the cosplay scene today. Some are well known, some a little more obscure, but all can be appreciated for their wonderfully creative and artsy flair. And of course, if you've always nurtured a soft spot for that mage in World of Warcraft, or found yourself inexplicably intrigued by Poison Ivy, these sexy cosplayers will have you stuck to that 'like' button.