The Duke of Edinburgh’s Award is a real and very British phenomenon; a perplexing mix of activities to challenge, empower and mildly endanger teenagers which concludes by setting them loose in the countryside with a map, a compass and a pat on the back. Get Duked! wisely focuses on the weirdness of the expedition portion and exploits its eccentricities to delightful effect.

The dreadful behaviour of a trio of toilet-detonating mates – Duncan, Dean and DJ Beatroot – finds them ‘volunteered’ for the DofE scheme as a final chance to straighten up. Baffled by both the welcome video and the very concept of orienteering, the boys reluctantly hit the Highlands-bound minibus armed with all their survival essentials: sick beats, jelly sweets and box-fresh trainers.

Making the journey alongside them, easily overlooked but better prepared, is homeschooled DofE enthusiast Ian (Samuel Bottomley) with his laminated checklists. New teacher Mr Carlyle (Jonathan Aris) provides maps, half-hearted oversight and pessimistic comments about free-range teens and the motley crew’s odds of making it to the campsite rendezvous.

The sense of buoyant energy and mild menace is established early with a banging UK hip-hop soundtrack and cleverly fidgety edit. As the boys acclimatise, DJ Beatroot (Viraj Juneja) gets busy stickering every surface in sight to introduce his singular sound to the locals while we are equally busy noticing that something is dreadfully wrong in the great outdoors.

The first of the many glorious things about Ninian Doff’s unashamedly bonkers film (and the only one we can really share without ruining the ride) is its young cast. Their easy chemistry endears us to the characters before they have each made more than a superficial impression and carries us through the worst excesses of silliness later in the story when we know them well and are rooting for one and all.

The initial challenge of making it to camp before dark without getting mud on Beatroot’s kicks grows more complicated when Duncan (Lewis Gribben) skins up with the map. As Dean (Rian Gordon) comes up and the boys fall out, a different kind of darkness crosses their path and the Glaswegian misfits are forced to team up to fight a class war for their very lives.

Get Duked! initially appears to have relocated Joe Cornish’s alien vs teen masterpiece to the Highlands but director Ninian Doff veers off track as amiably as his protagonists and Attack the Loch morphs into an anarchic hybrid of Sightseers, The Hills Have Eyes and The Queen. The Duke and Duchess (Eddie Izzard and Georgie Glen) are the tweedy villains in pursuit of our heroes and of a more genteel way of life but you’ll only have eyes for the boys.

Despite daft subplots involving hallucinogenic rabbit droppings, raving farmers, the inept local plod and a notorious bread thief, nothing can bring this cracking comedy down. Viraj Juneja gives a star-making turn as good boy gone gangsta DJ Beatroot but the four leads are universally great, selling every setup and gag and keeping us invested in their evolving friendship until the bloody end.

Sweet, sinister and straight-up gross, Get Duked! is available on Amazon from Friday 28th August