After a brief posting to the 16th National Service Battalion in early 1952, Badcock entered the Officer Cadet School, Portsea, on 12 July 1952, and was commissioned as a second lieutenant in the Royal Australian Artillery on 13 December that year. This was followed by a short posting to the 14th National Service Training Battalion, then a posting to the 1st Field Regiment in 1953. He returned to train national servicemen in 1955–1957. On 26 May 1956, he married Denise Maureen MacMahon in the Methodist Church at Manly, New South Wales. The couple had three daughters – Carey, Kim and Susanne. Badcock was posted back to the 1st Field Regiment in 1957–1958. A junior staff officer in the Directorate of Military Operations and Plans at Australian Army Headquarters from 1958 until 1961, he was promoted to temporary captain in 1958, and substantive captain in June 1960. On 6 February 1961, he was posted to the 4th Field Regiment, and the same year changed his surname to Badcoe. On training exercises, Badcoe was aggressive and energetic. He was also a quiet, gentle and retiring man who confided mainly in his wife and had a dry wit. His colleagues found him inscrutable. He avoided boisterous mess activities and preferred reading military history. Short and stocky, a teetotaller who did not smoke, he wore horn-rimmed spectacles and regaled his colleagues on military matters when off-duty.