Also known as the Fancy Dress competition or more recently as CosPlay [Costume Play].
Usually held on the Saturday night, usually starts late evening with rehearsals being block booked in the main programme room during the day sometimes followed by the convention disco (not all Eastercons have a disco-type events).
In recent years a Cabaret has sometimes been added before or after the Masquerade, where fans perform a 3-5 minute performance.
With the increasing interest of CosPlay in the US and increasing interest and participation in media cons and events such as Comic Con. The masquerade could potentially be used as a CosPlay showcase at the convention attracting a younger and more diverse membership.
It is true that some people wear costumes just to attend Eastercon - even if they are not participating in a formal Masquerade. This is generally known as a Hall Costume. They may be wearing a costume specifically from a film or tv show or from a novel, or it may just be something out of the ordinary that you might wear to a party. With the increased interest in CosPlay Hall Costumes are becoming more prominent at Eastercon members choose to participate or not and its not unusual to see people at the convention bar in a variety of clothing ranging from costumes based on TV and movies to jeans and a T shirt.
Hall Costumes are perhaps the best known aspect of conventions outside convention members because it is usually all that the Media focusses on and has become the public perception of conventions.