[3][4] Wagner describes himself as "a pretty badly adjusted youth" in America, fighting and getting into trouble, and says he "benefited a lot from the added discipline of life in Scotland.

"[3] When he left school he joined a printing company, going to college on day release, until his aunt showed him an advert for editorial assistants at D. C. Thomson & Co. in Dundee.

and Whizzer and Chips,[5] they also went on to write for girls' and boys' adventure comics, including strips like "Yellowknife of the Yard", about a Native American detective in London, drawn by Doug Maxted, for Valiant;[9] "Partridge's Patch", about a friendly rural policeman and his dog, drawn by Mike Western, for Jet;[10] "The Can-Do Kids" for Lion,[11] and boarding school serial "School for Snobs" for Tammy.

[5] After that he quit comics for a time, taking a variety of jobs,[8] including as caretaker of an estate in the Scottish Highlands[6] and dredging on a barge.

[12] In the autumn of 1974 Pat Mills had been tasked with developing Battle Picture Weekly, a new war-themed title for IPC to compete with D. C. Thomson's Warlord.

[8] Wagner continued to write for girls' comics, including scripting gymnastics strip "Bella at the Bar" for Tammy,[13] and was appointed editor of the ailing boys' weekly Valiant.

Wagner suggested the new title needed a cop story, and his proposal, "Judge Dredd", took the Dirty Harry archetype further, imagining a violent lawman, empowered to dispense justice on the spot in a future New York.

[8] The first published episode appeared in issue 2, based on a script by Peter Harris, rewritten by Mills[2]: p. 48  and drawn by Mike McMahon, which alienated Ezquerra.[19]: pp.

One, "Robo-Hunter", a private detective-style character who specialised in robot-related cases, was initially drawn by José Ferrer, but his pages were partly redrawn by Ian Gibson, who became the strip's regular artist.[19]: p.

49  The other, "Strontium Dog", a sci-fi western about a bounty hunter in a future where mutants are an oppressed minority forced into doing such dirty work, was created by Wagner and Ezquerra for Starlord,[8] a short-lived sister title to 2000 AD with higher production values.

96  For the revived Eagle they wrote "Doomlord", "Joe Soap", "Rebel the Police Dog", "Computer Warrior", "The Fists of Danny Pyke",[21] "Manix" and "The House of Daemon"; for Scream!

[24] During this time Wagner wrote the documentary strip "Fight for the Falklands" for Battle, without Grant who had no interest in war stories,[21] and "Dan Dare" with Pat Mills for Eagle.

Outcasts was well received, though it never sold in great quantities, and this success led to the pair writing Batman in the pages of Detective Comics from issue 583, largely with Norm Breyfogle on art duties.

123–124  and they split their work between them: Wagner kept "Judge Dredd", while Grant continued "Strontium Dog" and "Anderson, Psi Division" and became the sole writer of Detective Comics.

John Davidge was appointed as publishing director in 1989, and within a matter of weeks was confronted by Wagner, who emptied a large bag of Judge Dredd merchandise onto his desk, pointed out he had received no royalties for any of it, and threatened a creator walk-out over the issue.

Wagner did most of the development work, and wrote three of the five strips in the opening line-up, including "America", illustrated by Colin MacNeil, which examined the totalitarian nature of the Judge system through the story of a young woman who becomes a pro-democracy terrorist, and "Young Death: Boyhood of a Superfiend", with art by Peter Doherty, which told the origin of Dredd's arch-enemy Judge Death in humorous style.

[19]: pp.138–140  While his efforts were concentrated on Dredd in the Megazine, Wagner took a break from writing the character in 2000 AD, replaced by Garth Ennis,[19]: p. 141  Grant Morrison,[19]: p. 162  Mark Millar and others.

167 Wagner was initially involved in Toxic!, an independent weekly anthology launched in 1991, but, aside from two Bogie Man serials co-written with Grant, most of his proposed stories were rejected and he withdrew from the project.[19]: pp.

142–143  One such proposal, "Al's Baby", a comedy about a male mob hitman who becomes pregnant, drawn by Carlos Ezquerra, ran in the Judge Dredd Megazine in 1991.[19]: p.

Wagner and Grant reunited in 1992 for Judgement on Gotham, a hit graphic novel teaming up Judge Dredd and Batman, co-published by Fleetway and DC and featuring painted art by Simon Bisley.[19]: pp.

[31] In 1997 he wrote his first original graphic novel, A History of Violence, a contemporary thriller about an unassuming small-town man whose background in gang crime comes back to haunt him, drawn by Vince Locke for the Paradox Press imprint of DC Comics.

230  Since 2005 he has shared the character with other writers, including Gordon Rennie, Robbie Morrison, Si Spurrier,[19]: p. 236  Al Ewing and Michael Carroll.

[5] 1995 saw the release of Judge Dredd, a big budget version of the comic directed by Danny Cannon and starring Sylvester Stallone.

[5] A second attempt at adapting the character to the screen, entitled Dredd, was released in September 2012, directed by Pete Travis from a script by Alex Garland, and starring Karl Urban.