If you had told me a year ago that I would need rules for player-run religions, I’d have disagreed. It sounds like a weirdly specific edge case that’s unlikely to come up in play. And yet, here I am, deep into a campaign where my players have invested a ton of resources and time into spreading the word of a god they made up.
As it turns out, the growth of a new religion is a tricky thing to model. I’ve gotten this far just using fiat and my own judgement, but it feels ‘floaty.’ I’m usually very comfortable with fiat, and advocate using it more often in games. In most cases, though, fiat is only a few steps removed from structure. If a player wants to do a weird thing in combat, I know how to quickly construct a ruling, because I know how combat works. But I have no point of reference for how an idea spreads through a game population. I need to pin down some guidelines.
The way I figure it, there are four basic phases of growth to worry about.
First, there’s the initial establishment of the religion. You’ve gotta get your core true-believers going. Gotta find your 12 apostles: the folks who will sell your religion to the masses. There’s really nothing to codify here, because this bit should be handled through normal play. Maybe the PCs make some eloquent speeches, or maybe they just fake some miracles. However they get it done, it will be about planning and execution on the player’s part, which is something the referee should be able to respond to. Any rules would just get in the way.
Getting out of phase 1 requires the players to successfully get some NPCs excited about their new faith.
In phase 2, the core believers have organized themselves into a cult. They are spreading the word, and the religion is growing slowly.
This is a hard phase to break out of. Cults are small, and generally composed of social outcasts. They have to meet in secret, and most people who hear about what the cult believes will think it’s nutso. Each Haven turn, the cult’s numbers grow by 1d4 * 10%, rounded up. So if you’ve only got 12 people to start with, and you roll a 1, then the cult grows by 10%. Since 10% of 12 is 1.2, that means the cult gains 2 new members that month.
Generally I try to avoid percentage based math when I design a rule. I was homeschooled, so I have no math skills, and much prefer mechanics that keep shit simple. But, in this case I think the benefit outweighs the difficulty. It’s the simplest way for the cult’s growth to accelerate as it grows larger. Plus, since it’s all based on increments of 10%, the math is simple: just move the decimal place one space to the left, then multiply by whatever number you rolled on the d4, and add the result to your previous total.
If the players want to, they can continue to grow the cult with direct action, the same way they did in Phase 1. However, they’ll only ever be able to get a few people at a time that way. The hard work of growing a cult is the boring process of preaching, providing spiritual guidance, offering services, reaching out to the disenfranchised, etc. Not really the work of adventurers. It’s best for the party to remain a guiding hand, and let this work happen in the background.
Phase 2 ends when the cult has 1000 members.
In phase 3, the cult has evolved into a full fledged new religion. The faithful, emboldened by their numbers, begin to operate more in the open. Most people in the community will have have some idea of what the faithful believe, and most will be tolerant, even if they don’t agree. Of course, the reactionary forces of more established religions will be ramping up their rhetoric about the evils of this new faith. But, the average person doesn’t have a horse in that fight.
Once a religion reaches this stage, there’s no need to track actual member counts anymore. Instead, the faithful are counted as an abstract percentage of the total population, starting at 0%. Each haven turn, the religion’s hold over the population increases by 1d4. So, if you roll a 2 on the first haven turn, then 2% of the population has converted to the new religion. If you roll a 3 on the next haven turn, then 5% of the population has converted, and so on.
The idea is that now that your religion is both well known, and not considered crazy, all the folks who are slightly more predisposed towards your tenets than they are to the tenets of other faiths are making the switch. They aren’t the same breed of passionate true believers that the cultists were, though. The true believers are still there, but they’re in the minority now.
The new folks are mostly here because their old religion wanted them to attend services on Tuesdays, and the Wednesday services YOUR church requires are really more convenient for their schedule. Of course, if a new faith showed up with THURSDAY services, a ton of them would leave for that one.
Phase 3 ends when the new religion reaches parity with the other religions in its environment. So, if there’s only 1 other religion, phase 3 ends when the new religion is at 50%. If there are 2 other religions, phase 3 ends at 33%, and so on. If you play in a game with tons of different religions, it may be best to simply drop Phase 3, and skip straight from Phase 2, to something similar to Phase 4.
In Phase 4, growth more or less stops. If the players want, it can continue at (1d3 – 2)% each Haven Turn, but that’s not really going to result in much. At this point, the supply of willing converts has been exhausted. Anybody who joins the religion from here on out will be someone who consciously decided against joining the religion at some point in the past.
At this point, the religion has successfully established itself. For many faiths, this will be the endgame. However, players are rarely satisfied with an equal share of the pie. They want all of it. So, if the players want their religion to continue growing, they can do that. But, from here on out, each bit of growth will again require direct action. Not by preaching, but with dramatic public displays that either push people towards the player’s religion, or away from competing religions.
For example, if the leadership of religion X is exposed as corrupt, people’s faith in that religion will be shaken. Some of them, will leave, and as a result, the ranks of the player’s religion will grow. Likewise, if the player’s religion engages in a huge campaign to fight poverty, some people will be inspired by that generosity, and will convert. Those are just two out of millions of possibilities. It’s up to the players to orchestrate a public display, and up to the referee to determine whether those displays are significant enough to count.
Whatever the specifics, though, a successful public display causes the player’s religion to grow by (1d6 + 3)%.
Of course, the players could orchestrate these public displays during Phase 2 if they wanted, but given the investment of time required, it’s not really worth it to pursue until after the religion has gotten as big as it’s going to get on its own.
And there you have it, a system for modeling the spread of a religion, from inception, to complete cultural saturation. So…what is this system good for? What does founding a religion actually do?
In my case, my players started a cult because they wanted to disrupt the majority religion. The more successful their cult is, the more distracted the majority religion gets. They can’t orchestrate crusades against their neighbors if they’re focusing all of their energy fighting the spread of the player’s cult.
More than that, though, establishing a religion has allowed my players to influence the basic worldviews of the NPCs in their environment. After all, what is a religion but a set of shared beliefs and rules to live by? The same system could easily be used to model the spread of a philosophical school or political movement.
In other words, establishing a religion allows the players to set the rules by which people live. If they don’t like living in a world where slavery is normal, spreading a religion gives them an opportunity to change that.