Are superhero films also sci-fi films? Are they a subgenre of this larger storytelling form, or are they a genre in their own right? Some would argue that super heroes are their own genre with their own set of iconic characters, classic stories and narrative conventions. Superhero films frequently use sci-fi elements in their stories: aliens, mad scientists and advanced tech crop up frequently, but they use these in a way distinctive to their own genre. Some have argued that if the conventions of a set of films are well known enough that they can be parodied, this makes them a genre. Kick-Ass distills the essence of the superhero film as a genre in the same way that Blazing Saddles sums up what a western is.

Iron Man 3, which opened at cinemas nationwide last Thursday, has many sci-fi elements within it. Robert Downey Jr's Tony Stark is in charge of a technology empire and is a scientific genius capable of building incredible machines. Despite this, he cannot sleep and his relationship with his girlfriend Pepper Potts (Gwyneth Paltrow) is falling apart. At the same time, a terrorist known as the Mandarin is attacking America with hi-tech man/machine hybrids.

It all sounds very much like a sci-fi film, also when you consider the plot is constructed around a series of high octane action spectacles, like a lot of recent sci-fi films are. One of the film's strongest scenes involves Stark using all his Iron Man skill and technological agility to save people falling from a crippled Air Force One. The villains are classic sci-fi evil cyborgs, and this film borrows very much from the Superman 2 ethos that we empathise with the hero the most when he is hitting someone capable of hitting him back.

The movie also has a lot which is characteristic of superhero films and not sci-fi films - mainly that it is built around one strong performance, as opposed to an engaging story. Iron Man 3 is mainly sold on Robert Downey Jr's charisma, which is extremely entertaining. He has the acting chops to carry the emotional scenes and is brilliant at the comedy moments, especially in one-on-one dialogue exchanges with Don Cheadle's War Machine or a child played by Ty Simpkins. Cheadle is also very good in his supporting role, as are Paltrow and Guy Pearce. A special mention should go to Ben Kingsley, who delivers an astonishing transition as the Mandarin and can almost match Downey Jr for being serious and comic in the same film.

The story of Iron Man 3 is almost inconsequential, which is not typical of plot driven sci-fi films, but the action and general sense of a film not taking itself too seriously carries the viewer through.

Iron Man 3 has more in common with the conventions of the superhero genre than that of a sci-fi film - conventions which are clearly defined enough in this film alone to make the case for superhero films being a genre in and of themselves. Downey Jr is stellar in the title role, with enough magnetism to carry the whole film, and all the other elements are present to make this a thoroughly enjoyable superhero movie. The final action sequence involving a horde of cyborgs and up to forty Iron Man suits is breath taking. In terms of sci-fi, Iron Man 3 lacks the main appeal but as a superhero film, it excels.