 At one extreme, the genre is used to speculate about future wars involving space travel, or the effects of such a war on humans; at the other, it consists of the use of military fiction plots with superficial science-fiction trappings.The term "military space opera" is occasionally used to denote this subgenre, as used for example by critic Sylvia Kelso when describing Lois McMaster Bujold's "Vorkosigan Saga".Space opera parodies are often themselves examples of space opera.