gratuitous

Given freely; unearned.

Also mentioned is the Rev. T. Stock, who has a tablet in St John's church [Gloucester] and "who with Raikes established the four original Sunday schools in this parish ... in 1780. From this small beginning sprung that gratuitous system of Christian instruction which has covered the face of England and Wales with schools."

Unjustified or unnecessary; not called for by the circumstances.

gratuitous violence

Good to see you Mr. Bond. Things've been awfully dull 'round here. […] Now you're on this. I hope we're going to have some gratuitous sex and violence!