Perennially popular, science fiction has been particularly prevalent in YA fiction through the sub-genres of dystopia and speculative fiction. Think Hunger Games, Divergent, and The Scorpion Rules.
Classic dystopia is set in a “perfect” world that spirals out of control, turning into a bleak, oppressed society. These are new or alternative worlds, or futuristic societies characterised by degradation in values, social hierarchy, terror and oppression. Tone and mood are dark. The worlds may be quite realistic or have elements of fantasy.
Speculative fiction moves away from imagination towards more realistically possible near-futures of major social or environmental changes, posing “what if” questions to the reader. A classic of speculative fiction that is enjoying a major resurgence in popularity is 1984, about a society where the government decides what is truth and controls its people every second of the day.
Don’t forget classic sci-fi: other worlds, aliens, advanced technology. Do Androids Dream of Electric Sheep? was turned into the film, Blade Runner. A Wrinkle in Time, Dune, The Martian Chronicles, The Martian, and The Lunar Chronicles are all examples that are worth reading.
