I think one of the most important decisions a GM has to make when planning their campaign set in the Worlds of 2000 A.D., and particularly Judge Dredd and Mega City One is when to set the campaign.
The when is a really big decision. It determines what has happened to the city, whether characters are alive or dead, etc.
For instance when deciding when to set your campaign in the history of Meg City One did you want your characters to be able to bump into Judge Dredd? If the answer is no you are probably best setting your campaign in the early days of Mega City Ones history and the Judges before Dredd was created.
The alternative is to pick one of the many times that the legend was not in Mega City One, such as when he was on Luna 1 or in the Cursed Earth. Although the drawback is he does return to the City. Which is fine if you are running a short campaign.
Or you can just do the obvious and pick any point in the city history and have the party not meet him. But for me the temptation would always be there to call upon the legend. Personally I’d chose the early history of the city because of the interesting story arcs that could be used. That could eventually cumulate into the development of the clones that produce Joe and Rico.
Let’s assume that you want Judge Dredd to be around, and the possibility of your players bumping into him. You now have forty years of Judge Dredd stories to inspire you.
But when do you set your campaign? Which of the major story arcs to you want your players to experience? Each of the main arcs have had an impact on the city in some way. The ones I grew up with were The Robot Wars, The Cursed Earth, The Day the Law Died, The Judge Child, and The Apocalypse War.
It’s very easy to have your party taking party in these events as they happen. For instance while Dredd is off on Luna 1 justice still needs to be kept in Mega City 1. Maybe the criminals are feeling a little bolder while Dredd is off planet. Or your party are doing hit and run raids on Soviet judges during The Apocalypse War.
Naturally another thing to consider is which of the classic adversaries you want to have your party face off against. This will also determine when the campaign is set. Mainly because eventually the adversary ends up dead. The Angel gang is an amazing adversary for a party. But they died at the end of The Judge Child. Fink Angel died after The Apocalypse War. So this is something that needs to be considered. Unless you decide to play the what if? scenario. Such as what if the Angel Gang didn’t die?
EN Publishing has three source books now for the Worlds of 2000 A.D. WOIN system.
Which as you can see cover early classic story arcs. But definitely worth getting.
There is an excellent timeline here. The wiki page also has a cool list of major stories.
Don’t forget that there have been three earlier rpgs based on Dredd. There have been some great adventures for them, and really useful source books.
And finally there are the reprints in the Complete Case Files, of which there are over thirty volumes. You can usually pick these up for less that a tenner second hand from Amazon. Plus if you are after just one story arc there will also be a good chance there is a single graphic novel collecting the issues into a single volume.
I suppose the main point is that there is a wealth of material out there to support you in your campaign no matter when you decide to set your campaign in the history of Mega City One.