(cross-posted from my substack)

The Helicopter of Theseus

Modulating TTRPG Design

The Ship of Theseus is a philosophical thought experiment about the nature of identity. Roughly, it goes like this: imagine a wooden ship that has been in service a long time. Over that time its crew makes repairs, replacing rotten boards with new ones, etc. And, as it happens, over its long tenure every single piece of wood has been replaced at one time or another, such that none of the wood from the time that the ship was built remains. Is it the same ship? It’s a classic of dorm-room philosophy talk.

But I bring it up not to discuss whether it’s the same ship but to make the point that, regardless of your position on whether or not it’s the same ship, if you follow a strategy of piece-by-piece replacement, even if the pieces you put in are somewhat different than the pieces you pull out, you’re still almost certainly going to have a ship at the end rather than a helicopter. And this brings us to TTRPG design.

Chasing the dragon of modular mechanics

A lot of people express aesthetic preferences about how parts of games work. Some people want their RPGs to have grid-and-minis combat while others don’t. Some people want unified resolution mechanics and others want minigames. Some people want social interactions to be governed by mechanical systems and others want to freeform RP that sort of interaction. So the thought arises spontaneously in thinker after thinker: “What if we made the game modular and people could swap in modules that match their preferences while still playing the same game!?”. It’s a seductive idea, especially if your model of the TTRPG world is that there must be one game to rule them all. The problem is that it’s much easier said than done, because you can’t just swap in and out the parts of a machine on a purely aesthetic basis and expect it to work well.

If your TTRPG’s mechanical system is made up of N subsystems and you want to replace one of them, you’ll then have N-1 other subsystems exerting influence on the “negative space” where your replacement needs to go. That will influence how your new subsystem will work.

Game design is holistic

For a long time the Burning Wheel HQ crew and their fans believed that the subsystems in Burning Wheel were optional extras. They thought you could bust out the big complicated things like Duel of Wits when you wanted to, but you could also run things as simple versus tests, and the game worked fine with both approaches. Eventually what they acknowledged is that they couldn’t just dial complexity up or down in isolation, if you actually use the complex subsystem you end up making a lot more die rolls, so you potentially end up using your Fate and Persona points to influence those die rolls. Which means whether or not you run the Duel of Wits has an influence on how many of those points you use, which has an influence on the “economy” of those points – since the game’s subsystem for awarding those points is the same either way then you’ll have an abundance of points if you run everything via simple tests or a dearth of points if you run everything with the full subsystems. That has an impact on the subjective experience of play, which is the thing the game designer is trying to design.

SRDs

Even if it’s not strictly modular, designing a game by starting with a design framework or SRD can invite a similar dynamic – getting a new game that feels different from the thing you started with is no small feat. Starting from an “already working” baseline may look like a huge advantage for a designer but it’s really a tradeoff: if the structure isn’t already pointed in the direction you want it to go then you may find that interdependent systems have a lot of momentum and take a lot of work to shift. There seems to have been a resurgence in the popularity of SRDs lately, seemingly as a marketing strategy for the underlying game systems. My personal take, perhaps overly cynical, is that there’s a heads-I-win-tails-you-lose dynamic built into using them: If you make a great game built off of somebody else’s framework the framework gets some of the credit, but if you make a bad game you get all the blame. Remember the d20 glut? People blame the small companies that believed the story that the d20 system could do anything, not the huge company that pursued an intentional strategy of convincing people the d20 system should be the lingua franca of all TTRPGs.

Strict Constructionists

One of the things that tends to push systems to maintain their feel is that the “modules” usually have to interface mechanically with other modules. So you can try to make a more whimsical magic system for D&D, but if you end up having to explain how it affects the Hit Points, etc., of the target then it’s probably going to end up feeling pretty D&D-ish. A few years ago Michael Prescott wrote a blog post laying out a vision for a modular approach to TTRPG design that does the opposite, MOSAIC Strict.

The key feature of MOSAIC Strict is that you can’t reference mechanics from another module, just stuff that would make “in world” sense. So if you wanted to make a boxing module you could refer to a character’s weight (since that’s just a fact about the world) but not to something like a strength score or skill ranks, since you don’t know if the game has anything like that.

While I have no idea if it would be any fun to play a game based on MOSAIC Strict modules I think it’s a really interesting design exercise to make them. It can put a spotlight on your habits and preconceptions when you can’t use familiar solutions. For example, lots of character systems implicitly refer to the resolution system of a game, since what your character can do or how well they do it is a tried-and-true way of thinking about a character. So trying to make a character system that doesn’t do that can challenge you to think about what a character system is and what it does and how you could do it in a different way.

Jammed Up

A few days ago I saw that there’s a game jam running that’s trying to encourage people to make some stuff in the MOSAIC Strict design space. Since it’s premised around printing the modules on playing cards it’s even more space- and length-restricted than default MOSAIC Strict so I doubt I will enter myself (the wordcount and space constraints are something I really struggled with in my own MOSAIC Strict modules, probably to the detriment of how easy-to-understand the final texts are), but I always thought MOSAIC Strict was underappreciated so it’s nice to see activity around it.

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(Puzzle piece image from Pixabay)