Understanding Your Campaign World's Universal Laws

What universal laws characterize your fantasy TTRPG campaign? Not top-down ideas that informed the creation of the campaign, but rather universal principles like gravity or magnetism. Concepts that are prevalent throughout the world, but apparent to human understanding only after we work backward from the implications of in-game events. 

So what are your universal laws, and what they say about the campaign world?

Universal Law: Serendipity

Our long-running 5E campaign operates in a troupe style, where different characters come and go from session to session. I have employed various in-fiction conceits to explain these comings and goings, but the uniting idea is that the characters are separated and reunited with serendipitous frequency.

In the real world, we understand that the feeling of serendipity we experience when we run into an old friend on the street is just our tendency to focus on events that seem strange or special to us. We don’t think about all the times we didn’t run into an old friend while walking down that same street. Serendipity is a function of perception, not some subversion of random chance.

In contrast, in our D&D game, serendipity is a law of the universe. The characters, through some unknown characteristic as real as gravity, magnetism, or magic, serendipitously run into each other at just the right time. 

Universal Law: Process Inconsistency

Few fantasy RPGs attempt to simulate anything close to a particular historical period. The typical 5E campaign – judged from the classes, equipment, social structures, and magic items in the core books – is a dizzy mix of historical periods, cultural regions, and fictional inputs, from the early middle ages to the late renaissance, with some steampunk and even sci-fi elements thrown in for good measure.

It’s also developmentally static. Certainly wars happen, nations rise and fall, and the players will occasionally take part in world-shaping events. But technology and science doesn’t develop or change in the way that we see in the history of the real world. 

It has been pointed out – not inaccurately – that most low- and medium-fantasy settings are essentially post-apocalyptic, with the world’s high point of development in the rear view mirror, reflecting the dying earth stories that heavily informed the Appendix N of D&D. 

An alternate (or perhaps complementary) understanding informs our current campaign’s world: the world does not develop because it’s hard to replicate technological advances. In the real world, the industrial revolution was powered (quite literally) by the ability to produce superior devices, then disseminate those models far and wide. Once a better steam engine was available, everyone would eventually adopt it. People could reproduce a design anywhere in the world, and generally expect the same results.

In a world of magic, a particular mundane process or invention just isn’t guaranteed to work consistently across space and time. A side effect (or possibly, a direct effect) of magic’s super-real circumvention of physical laws is that it’s just hard to do something exactly the same over and over again. There are no assembly lines, no standardized blueprints, no proven concepts of engineering, chemistry, and physics that will work quite right 100% of the time. Industrial and scientific progress is still possible, but it’s more likely to be the creation of one person, group, or nation; the world remains a patchwork of incongruous societies and mad geniuses, where progress is simply less infectious than it was in the real world.