Laffin was a prolific author, writing over 130 books as well as many articles and short stories. Most of the books dealt with military issues, in particular the Australian Digger and World War I. More than 200 of Laffin's short stories appeared in Australian magazines.
In his fiction writing, Laffin used a number of pseudonyms including the name 'Carl Dekker' which was shared by the other Australian writers Keith Hetherington and possibly Gene Janes (qq.v). (Dekker was the main character of the adventure novels written under this name.)
Laffin's employment was in the fields of academia and journalism; his main interests were history and archaeology.
This is how the backcover of his autobiography describes him: 'John Laffin has had an extraordinary life as a journalist and editor, novelist and poet, wartime soldier, military historian and war writer, battlefield archaeologist, broadcaster, lecturer and public speaker, intelligence agent and specialist on Islam and the Arab world, and teacher in three of England's leading colleges.' (A Kind of Immortality : Volume I)