Take one widely regarded character or series, put it together with another similar property and you've got a hit. That's the guiding philosophy behind the movie-based crossover. At first, the idea was popularised by comics, but as film technology progressed, directors and production crews had their own ideas.
In the days before the entertainment scene was dominated by connected movies, crossovers had a tricky time making it to the screen. Studio ownership rights and the work needed to combine two popular properties made them far less common in the lead-up to the late 2000s.
Nowadays, crossovers mean big money in the movie business. The task of crafting a grand cinematic universe is an enticing prospect for both film-goers and studio executives. Some of these efforts have proven to be smash hits both critically and commercially while others have fallen flat before they even got off the ground.
Recently, King Kong vs Godzilla has arrived and it promises a showdown of epic proportions. It joins the ranks of many other mash-ups in a bid for box office success. Which other clashes of the titans made their mark in cinema for good or for ill? In no particular order, you're about to find out.
10. Frankenstein Meets The Wolfman
We kick things off with the crossover that started it all, the classic showdown that set the blueprint for all contemporaries to follow. Back in the 1930s, the horror went through a golden age with all the biggest monsters making their silver screen debut.
Dracula, Frankenstein, The Mummy and The Wolfman, all of them found great success thanks to several films that brought the original books to life in cinemas. Leading the charge at this time was Universal, who held a practical monopoly on the biggest names in horror media. While efforts like Dr Jekyll and Mr Hyde came out of competing companies, there was no question that Universal held the broadest offering.
With several monsters under their belt, ideas started floating around the studio in the early 1940s. The result was Frankenstein Meets The Wolfman, the very first film to bring together two famous monsters. To maximise the star power of the proceedings, Lon Chaney Jr and Bela Lugosi were both cast in the leading roles.
Proving to be a successful formula, Frankenstein Meets The Wolfman laid the groundwork for other titles like The House of Frankenstein and House of Dracula several years later. It's unlikely the crossover would have been so prevalent today were it not for this film.