Crossover fiction
Fiction that brings together characters or settings from separate works or franchises in a shared story or world.
Shared universe: A fictional setting in which multiple stories or works share characters, events, or continuity. Crossover fiction can join works already connected by a shared setting.
Narrative crossover: A story structure in which characters or plots from separate works meet within one narrative. This is the direct story-level form of crossover fiction.
Comic book crossover: A comic-book storyline that brings together characters or settings from separate series or franchises. Comics have made crossovers a recurring format for linking separate character series.
Adaptation: A work that reinterprets a story or source material in another medium or form. An adaptation transfers a work rather than necessarily joining it with another fictional world.
Fictional character: A person or other entity invented for a narrative work. Characters are the most common figures brought together across separate works.
Continuity (fiction): The consistency of events, facts, and character histories across installments of a fictional work. A crossover must decide how the continuities of its source works fit together.
Intercompany crossover: A licensed story bringing together characters owned by different companies. These stories test how separate corporate properties can coexist in one narrative.
Parody: A work that imitates another work or style for comic or critical effect. Parody can imitate several franchises without making their worlds literally coexist.
Fictional universe: A coherent imagined reality containing the places, events, and entities of a story or group of stories. A crossover must reconcile, combine, or deliberately juxtapose the worlds its works establish.
Worldbuilding: The creation of an imagined setting and its history, cultures, rules, and institutions. Combining worlds often requires explaining which setting rules remain in force.