Starring: Louis Ashbourne Serkis, Dean Chaumoo, Tom Taylor, Rhianna Dorris, Angus Imrie, Rebecca Ferguson, Sir Patrick Stewart, Denise Gough

THE legend of King Arthur has been inspiring mediocrity on the big screen for decades.

Writer-director Joe Cornish’s family-friendly spin on the sword in the stone continues the dispiriting trend, messily combining medieval magic with present-day growing pains for a quartet of underwritten adolescent protagonists.

Action set pieces lack variety and eye-popping thrills, repeatedly pitting schoolchildren against flaming-eyed skeletal warriors on horseback who are easily stopped with a swift blow from a sword to decaying bones.

A 12-year-old boy pulls a sword from a stone strring King Arthur’s evil half-sister Morgana (Rebecca Ferguson) in her subterranean lair.

She employs sorcery to reanimate fallen warriors to slay the young boy and steal Excalibur.

Humour in Cornish’s script is skewed towards the youngest members of the audience, who might giggle with glee at comic buttock nudity or thrill to scenes of kids wielding traffic signs as shields in the hard-fought battle against ancient evil.