Why is Mothership, well, Mothership? Put another way, why isn’t it Basic Roleplaying, or Call of Cthulhu? The core mechanics are all very similar; basically everything in Mothership that isn’t specifically about starships is adapted from Call of Cthulhu in one way or another. And that little starship aside does point to the answer: The reason Mothership is Mothership, Call of Cthulhu is Call of Cthulhu, and neither of them are BRP has to do with the specificity of their missions. Both Call of Cthulhu and Mothership frame their ideal game experience as horror, which lends itself to specific mechanics in the designers’ eyes. Mothership more specifically is science fiction horror, so the designer adds rules about spaceships and space travel. Specificity isn’t limited to genre, though. Mothership is also intended to be light on mechanics; famously the game has no mechanics for things like stealth which means that the adjudication of things like hiding and following are circumstantial and entirely in the lap of the GM. Whether you agree with this mechanical decision or not, it is deliberate and it is specific.

While specificity of game outcomes is produced by having more and more concrete rules (Mothership’s take on stealth is completely non-specific, while a game with one or more stealth skills and a laundry list of modifiers would be much more specific), specificity of game design is much more interesting, especially as there’s an entire class of games that deliberately avoids it. When I looked at QuestWorlds, I saw a game designed to try and do everything, at the expense of doing anything in a particularly interesting or engaging way. It’s hardly the only generic game, and one could make the same complaint and direct it at Fate, or GURPS, or Savage Worlds.

But hold on. If we go back and look at Mothership again we have, broadly, a fairly non-specific game. Yes, it’s about space horror, and the character options are tuned to space horror. The GMing advice is very good. The layout is very good. The game, though? It’s, outside of the space horror part, stripped down Call of Cthulhu. So where does that Mothership ‘vibe’ come through besides the design ethos? A good part of it is the modules (hardly a controversial opinion), but I think a specific and interesting point is that the modules bring with them hyper-specific mechanics. While GURPS has mechanics meant to be at the level of physics and D&D has mechanics which reinforce genre, Mothership has a good chunk of its mechanics corpus supporting specific stories, designed for and included in the pages of modules like Gradient Descent and Another Bug Hunt. And this is kind of important: While Mothership clearly takes inspiration from the DIY and hack-and-borrow ethos of the OSR, it’s presented a bit differently. The modules, in addition to providing the setting and conflict and everything else for a solid few sessions of adventure, also provide the hacked/modified rules to make that adventure feel different or play different than the base game. It does make me think, though: If you’re hacking the rules (or using the designer’s hacks) for every module, how truly different is that from using a generic game? Put another way, what really makes Mothership different from BRP, really? It’s not rules, after all.