It's getting more difficult to tell at a glance if a film is designed to be a comedy-horror or whether it's just meant to be frightening. With some older films now seeming more laughable anyway, it's no wonder there's confusion over what's intended as light relief to offset the gore and what's meant to be an outright horror spoof. If you've watched any number of genre mashups, you'll know that it's not a matter of black and white - there's a gradual descent from horror into comedy. But is there a perfect ratio?

      Mixing horror with comedy first occurred in the 1920s when stage productions wanted to lighten the drama by adding laughs to the likes of 'old dark house' mysteries such as The Cat and the Canary. Laurel and Hardy then latched onto the idea, mixing horror elements into their short films during the 1930s, including A Live Ghost and The Laurel and Hardy Murder Case. Comedian Bob Hope jumped on the bandwagon with The Ghost Breakers in 1939, aas well as his own idiosyncratic take on The Cat and the Canary the following year.

      1948 brought the first Abbott and Costello Meets.., which mixed their vaudevillian double-act with the Universal horrors of Frankenstein, Dracula and the Wolf Man. A&C Meet Frankenstein was such a hit that is spawned a total of five A&C Meet.. (insert monster here) films and gave the duo a new lease of screen life. Dean Martin and Jerry Lewis joined in the fun in 1953 with Scared Stiff, a loose remake of Hope's The Ghost Breakers. In 1959, the legendary Roger Corman added to his growing oeuvre with A Bucket of Blood, which grafted satire onto the mix, and in 1960, he made The Little Shop of Horrors (later remade by Frank Oz in 1986), in which a florist's assistant cultivated a carnivorous plant. The film was based on a short story by John Collier called Green Thoughts and has since become a much-loved cult item.

      The Evil Dead sprang up in 1981 and was the first cabin-in-the-woods story intended to be a comedy-horror due to its low budget and cheap special effects, although it was also quite terrifying on occasion. (The British authorities failed to see the joke and included it in the notorious 'Video Nasties' ban of the early '80s.) The 2013 remake, however, seemed to completely forget about the comedy aspect, which is surprising given that both original director Sam Raimi and star Bruce Campbell where involved in its making. After the success of Universal spoof Young Frankenstein in 1974 and Dracula spoof Love at First Bite in 1979, many comedies drawing on horror tropes for their subject-matter surfaced in the 1980s, Ghostbusters, Gremlins and Critters among the best-known. Even Steven Spielberg's big-budget homage Twilight Zone-The Movie was played as much for laughs as it was for horror, though one of the most successful mashups of comedy and horror was undoubtedly Fright Night (1985), which managed to be not only hilarious (at times) but also really scary, with Chris Sarandon creating a classic vampire in undead Jerry Dandridge to rival those of Bela Lugosi and Christopher Lee.

      Films like Dead Alive (1992), Re-Animator (1985) and even Peter Jackson's inaugural Bad Taste (1987) all contain slapstick elements that can add to (or sometimes subvert) the horror, and both Re-Animator and Bad Taste have also become cult films now, probably due to Jackson going on the bigger and better things in the case of the latter. The special effects in low budget films often leave their makers little choice but to go the comedy route, as no one could take them seriously in any event!

      Moving into the '90s and early 2000s, spoof horror films were showing up by the dozen. It seemed that comedies which made fun of horror themes were the new horror in themselves, with Shaun of the Dead, Hot Fuzz and The World's End being immensely successful for the partnership of Simon Pegg and Nick Frost, and being collectively categorised under the sobriquet of the 'cornetto trilogy'. The folks behind the Scary Movie franchise also tried their hand at genre cross-dressing, moving onto Epic Movie, Disaster Movie and even Date Movie, none of which worked as well and channeled them back to comedy with The Haunted House 1 and 2 in 2013 and 2014.

      'Fourth wall' breaks are becoming more and more prevalent within comedy-horror films, with Scream (1996) knowingly referencing the familiar horror tropes from slasher films of the 1980s and The Final Girls (2015) stepping literally from one horror film into another. Tucker and Dale vs Evil (2010) is a hilarious twist on the typical cabin-in-the-woods horror concept, utilising role-reversal and exploiting the stereotypes gleaned from a multitude of the same old tales. The Cabin in the Woods (2011) used the same idea only a year later, but with a bigger budget and some neat dimensional twists and turns. An equally original take on Lovecraftian themes was provided by Don Coscarelli's inventive John Dies at the End (2012), which managed to not only be funny but chilling and faithful to its source material at the same time.  

    Severance, a 2006 film from Christopher Smith and James Moran starring Andy Nyman, Danny Dyer and Tim McInnerny employed the cabin-in-the-woods theme to great effect for its tale of a group of co-workers on a bonding trip to the country, where they gradually begin to realise that they've fallen prey to unknown forces. This comedy-horror is packed full of hilarious moments and witty humour, and its focus on the more outrageous elements of other, serious fare was matched by more of the same from other directors: Black Sheep (2006), The Cottage (2008) and Doghouse (2009) being but some of the efforts designed to laugh at ideas that previous films have depended upon to make us scared.

      Død snø (Dead Snow) was a 2009 Norwegian film, and arguably the closest to a 50/50 split of comedy and horror. Based on the idea of Nazi zombies, it was (over-the-top) gory, horrific, but also full of slapstick moments. The sequel was even funnier than the first, though not as spooky. Dead Snow was but the latest example to show that the fad for comedy-horror isn't yet over, and that the spoofs keep on coming (quickly sidestepping RIPD-3D). Roman Polanski's Dance of the Vampires (1967) may have started the modern trend (though it was neither particularly funny nor especially horrific) but the likes of Life After Beth, Warm Bodies and Bad Milo are continuing the mickey-takes well into the new millennium.

      A little comedy relief can take the edge off the most horrific of subjects; too much can topple them into farce. But many of the films mentioned above got it just about right. So whether it's The Rocky Horror Picture Show, The Addams Family or just the very idea of someone getting his head knocked off by a zombie - what do you think makes the perfect comedy-horror film? Tweet your suggestions to @Hemlockbooks!