[2] Law began to act, making his professional stage debut in 1872 at the Theatre Royal, Edinburgh.

[3] In 1877, Law married actress Fanny Holland, with whom he appeared with the German Reeds at the Gallery of Illustration and St. George's Hall.

Law later appeared on stage at the Savoy Theatre as Mr. Wranglebury in the companion piece Mock Turtles in 1882, and as Major Murgatroyd in Patience in 1882, filling in for Frank Thornton.

He retired from acting following a final engagement at Savoy Theatre, in 1881, to turn his attention completely to writing.

That year he also wrote a musical farce, Mr. Guffin's Elopement, in collaboration with George Grossmith, for Toole's Theatre, starring J. L.