How many movies have Cliff Burton and Lars Ulrich acted in together?

They have worked on 13 movies together! Their first movie together was Metallica: [1983] Kiss the Stone (1983) while their highest rated movie together was Metallica: Ride The Lightning (1985). They have not worked together since Metallica: 40th Anniversary - Live at Chase Center (Night 2) (2021). They are most known for their music films together.