Cameron came to this low-budget science fiction movie with a single directorial credit to his name, the silly exploitation film Piranha II: The Spawning. The best that Schwarzenegger could boast from his screen career was a touching turn in Stay Hungry and an attention-grabbing appearance in the body-building documentary Pumping Iron. Both would go on to bigger things, but none that would equal the imagination or vigour of this frenetic thriller.

Already Cameron's favourite themes are evident in this taut, economical tale of the duel between a killer robot (Schwarzenegger) and his human nemesis, Reese (Biehn), over Sarah Connor, the woman (Hamilton) whose unborn child will in the 21st century save humanity by destroying the machines that have taken over the world.

In Cameron's films it is always the women who are the natural leaders, the survivors. Also, from a director who is famously in love with technology, the film is obsessively technophobic. The secret of its success is certainly not in its originality - science fiction author Harlan Ellison threatened legal action until he was awarded a writing credit - but lies in its relentless energy, and Schwarzenegger himself as the taciturn monster, who in the course of the action delivers fewer than 100 words of dialogue.