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GameMastery Guide / Creating a World / Parallel Words

Creating a Parallel World

Source GameMastery Guide pg. 168
To create an alternate reality, simply take the existing world and change any one event or factor, past or present. From that point, it’s a matter of extrapolation, tracing down the many routes that history could take given your change and picking the resulting world that seems like the most fun to play in.

For example, let’s say you want to create a parallel world in which the evil wizard-king, a recurring antagonist in your campaign, was never born (or better yet, was killed early on in his career by alternate versions of the PCs). Upon entering the world and discovering its difference, the PCs may initially rejoice. Yet perhaps they haven’t ever stopped to consider that, without the strong king to hold things together, his many dukes and barons would launch a war of succession that would kill thousands. Perhaps wizardry has been outlawed by zealots determined to never suffer such oppression again, and even good-aligned wizards are burned at the stake. And can the farmers and townsfolk defend themselves from monsters without the harsh but effective royal guard? Any time you make a change to your world, ask yourself what could go right, and what could go wrong—many times, the best challenges come from changes that, on the surface, seem positive. In this example, not only have you created a new world for your PCs, but you’ve also forced them to revise some of their basic beliefs.

While for most games it’s not necessary to explain the theory behind a parallel universe, such considerations can be fun for you as a GM. Did some cataclysm tear reality in two, creating parallel worlds evolving separately? Is it a naturally occurring phenomenon, or intentionally caused by some great wizard? Perhaps spells like wish create alternate realities to accommodate the caster’s flagrant breach of probability. All of these are academic questions, except for one: how to travel between the worlds. If you want to create a magical or scientific portal for your PCs to jump through, and follow it with another allowing them to return home, that’s perfectly valid. Yet you may want to make jumping between realities more complicated, the better to lead your party on quests and adventures, and to this end it helps to know the underlying structure of your realities.

As mentioned above, one model is to think of reality as a tree, with the PCs marking the end of a given branch. Every choice, event, natural law, or other discernible characteristic for its timeline has caused a branching, and the seemingly linear path back to the tree’s root is their history. Yet while that route is all they can perceive, every road their world didn’t take exists alongside them in the tree’s canopy, just waiting for them to jump between branches. As with an actual tree, those realities that branch closest to the PCs’ end point are easiest to reach—a world in which the events of yesterday turned out differently is comparatively easy to jump to compared to a world in which the PCs’ home nation was never founded, and the latter might require more powerful magic or a series of jumps through interstitial realities. This model also reinforces one piece of GM advice: while it may be tempting to alter a number of factors in your world at once, the ramifications of a single change are usually more than enough to keep you busy, and changing too many runs the risk of overwhelming your players. Keeping the worlds’ point of divergence identifiable is half the fun of alternate realities.

Archives of Nethys

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Creating a Parallel World