Elite boarding schools have been a favourite microcosm for film-makers to explore over the years: as the crucible of revolution in If…., the breeding ground of spies in Another Country, and the vessel of intellectual liberation in Dead Poets Society. Despite one or two nods and winks (including a picture of Malcolm McDowell in If… getting plugged in the face with an airgun pellet), this watchable if undemanding jape opts to take a very different tack: a teen comedy-horror with little aspiration to make any bigger points, just happy to chase its group of shrieking and bellowing schoolkids around an educational establishment’s venerable passageways and adjacent woodland.

Strangely, the coincidence of the real-world news cycle has given Slaughterhouse Rulez an unlikely topicality: a giant fracking drill in the school’s grounds has disturbed a pack of ravenous subterranean creatures, which emerge on a mission to turn any human they encounter to mince. Presided over by Michael Sheen at his most oleaginous, the student body are the usual mix of hyperviolent crypto-Nazis and snivelling weirdos (though the film-makers have tried to liven things up by adding St Trinians-esque sixth form “goddesses” and a Yorkshire-accented new kid, played by Finn Cole).

Most of the humour, such as it is, is provided by seasoned performers Simon Pegg (as an ineffectual housemaster) and Nick Frost (as an eco campaigner camping in the woods). Asa Butterfield proves his worth as a creepy bullied kid who is first seen flourishing a firearm; Cole and fellow lead Hermione Corfield (as principal goddess Clemsie Lawrence) do a decent job alongside.

Crispian Mills directs with zip, throwing things together with a breathlessness that largely distracts from the fact that, for a horror-comedy, Slaughterhouse Rulez is neither particularly scary nor especially funny. But it does have an amiable sort of charm.