Judgement Day is an adventure set in the then-future of 2018 that is set both in Mega-City One and on the prison moon Titan that orbits Jupiter.^[1] The evil Judge Cal, former tyrant ruler of Mega-City One, had his personality saved on a microchip before his death. The players must find the microchip and prevent it from being used, which would lead to the return of Judge Cal and his nefarious plans.^[2]

The adventure is divided into four chapters:

1. A Shot in the Dark: The players discover the body of a med-judge in the Labyrinth district
2. The Killer Fleas: The players try to visit the household of the dead med-judge, now quarantined due to an infestation of killer insects.
3. Trouble on Titan: The players travel to the prison moon of Titan
4. Cal Has Risen: The players try to protect Chief Justice McGruder from Cal.^[2]

Games Workshop (GW) first published Judge Dredd: The Role-Playing Game in 1985. The following year, GW released the game's first adventure, Judgement Day.^[2] The 32-page book was written by Marcus L. Rowland, with a cover by Brett Ewins. It also included 16 pages of player aids and cardstock miniatures of non-player characters.^[3]

Jason Kingsley reviewed Judgement Day for White Dwarf #75, giving it an overall rating of 9 out of 10, and stated that "Judgment Day is a solidly produced, value-for-money scenario, with well realised plot lines and individualised NPCs. Its plot is clever though slightly off-beat, but very much in keeping with the rest of Judge Dredd's world."^[1]