RPG History Tracks

Sparked by a discussion with James Mal and Sean McCoy

How to create a history/macro-trends for you RPG setting that is variable between different game masters but share enough elements between all instances that players have a shared experience?

For example, many of the artifacts and legendary items in the 1st edition AD&D DMG have been experienced by many players over the years in myriad campaigns despite the lack of no specific module or adventure featuring it (there are some exceptions such as the Hand and Eye of Vecna). Of course, the published adventures are also shared experiences even when fit into different campaigns. In a sci-fi setting, some of these shared events could be things such as the Vogons show up, Skynet awakens, Humanity becomes effectively immortal, the Clones revolt, the Empire fossilizes and fractures, and so on.

How to set this up?

• Create a list of topics that you care about in your setting. These are the "Event Tracks" that will things will progress along. 
• Define the starting condition for that topic. 
• Come up with at least two possible outcomes or paths for the topic an choose how likely each one is.
• Repeat for several steps, how many can vary by the topic and how much you'd want it to play out.

That defines the range of possible outcomes for all your topics. Now, decide what unit of time you want to use (year, decade, century, etc.) and then roll on the Event Tracks to see which track will advance. Then refer to your specific tracks and roll to see which path gets followed - keeping track of this results as you go.

You can stop progression at any time to use that as the current state of events.

(I should have put in a full integration result that carried across).

Example: Psionics (I've only done this one track as a quick feasibility test). Using decades as the time unit.

• Starting Condition: Some Psionic talents discovered
• Advance #1: Rolled 1: Psions create disasters.
• Advance #2: Rolled 5: Normals seek to control Psions
• Advance #3: Rolled 2: Psion Oppression/Expulsion
• Advance #4: Rolled 4: Psions survive in separate cities/regions

Things we know now: Psions exist, as a result of some disasters normal society had fear of them, sought to control them and that eventually led to them being pushed or fleeing into separate communities. Had die rolls been different, it might have resulted in the Zhodani Consulate or the complete, or very nearly complete extinction of Psions.