Royce made at least one attempt to enlist prior to being accepted in July 1918. On the first occasion he was discharged for making a misstatement on his attestation papers.
Like many other fellow passengers on the SS Zealandic which departed Victoria on 5 October, 1918, he was taken on strength with the 12th Battalion at the end of January 1919. He remained in France until 8 May 1919 when he was marched out for return to Australia departing in July 1919.
Not done with the military Royce re-enlisted in January 1940, serving nearly 12 months with the 6th Garrison Battalion before being discharged medically unfit. He married Ruby Williams in 1925 and together they had at least 10 children. Royce died at Grass Tree Hill on 25 January 1953 aged 55 years.