Mothership Post-Mortem

I ran a Mothership game for the Tuesday night group. It just wrapped up. Here's how it went, and the lessons learned.


Mothership is a relatively rules-light sci-fi horror game, designed to emulate the feel of things like Alien, Aliens, and Event Horizon, among others. It does the job well. Other people have reviewed the system before, so I'm not going to go super in-depth on that front, but I will describe my own experiences with it, and hacks I ended up using.

Character creation is smooth, as it should be. There's an expectation that characters will die pretty easily, and the creation process is pretty quick and painless. I mean, the character sheet is a FLOW CHART, which is really slick. The little pamphlet that is the entire game manual crams so much information in, I expect a LOT of games are going to take cues from it in future.

Mothership uses a d% roll-under system for most of its rolls, modified by skill percentages, and using advantage or disadvantage as necessary. It works, but also means that rules-as-written, there's no way to improve existing skills, and that more advanced skills are paradoxically easier to do than the easier ones, yet still prone to the same ballpark failure rate, which, depending on your attributes, can feel Not Great from the player perspective.

After a session or two, I implemented some hacks.

  1. Athletics, First Aid, and Zero-G can be taken an additional time for double the bonus.
  2. Expert and Master skills that have known prerequisites that are applicable to the situation may add those prerequisite skill ratings to the roll.

These worked really well. It allowed characters to get a bit better at things, and not feel like specialized points were wasted.

Mothership also has a Stress mechanic. Use it. I neglected to enforce it as hard as I could have for a few sessions, and it really helps with the mood, as well as incentivizing being on the lookout for ways to relieve it, or drilling in avoidance, rather than confrontation.

The Combat mechanics were another thing I hacked. Rules-as-written, it's an opposed roll, with one character rolling their Combat score, and the opponent rolling their Armor Save. The winner is whoever rolls under their stat by the least, Price is Right style. In practice, this is clunky. It requires JUST ENOUGH math to slow things down and get in the way. It also has that problem where you can roll your dice and hit, but then get told you missed because the other guy dodged.

I ended up ruling that if you roll to hit and hit, you hit. A successful Armor Save on the opponent's part cuts the damage you do in half. It's way smoother.

Shotguns and Flamethrowers are deadly. Don't fuck with them. One of my players blew themselves up with their own flamethrower. It was awesome.


My pitch for the game was as follows.

You've been adrift for about 12 days. Your last job went wrong, and left your poor craft crippled, lost, and far from anything that can be considered home. Fuel, life support, rations, parts, all either gone or running low. Just barely puttering along on auxiliary power, some very hard questions were looming.

Then, the sensors picked up a signal. A big one.

You pick your way carefully through a field of debris, and rising up ahead of you is a massive ship. Easily the size of a colony ship, all blocky angles, huge bulkheads, and dark spires. Still, though, as Egan, the comms officer sweeps it with sensors, you learn that at least parts of it are warm. Some of it has atmosphere.

"Cap, I know you're not a praying woman, but this could be the answer to ours," Egan says to the room at large. "If parts of that are warm, that means there's something generating heat, which means fuel. Vessel that size will have parts-a-plenty to try to cobble together some ways to fix the engines and life support, cryo-tubes, plus the giant holes in the hold. And if it's warm, that means it had people, which means we've got a good shot at finding some goddamn food and water, so we don't have to eat Simmons." There's a slight edge in his voice. That was not entirely a joke.

The Captain folds her arms and stares at the space hulk. It looms, lifeless, hanging still in the black. "Any answer to hails, Egan?"

Egan, holding one earpiece to his ear, says "Not yet, Cap, but I'll keep trying. Did pick up the standard ID signal though. Identifies as The Hand That Sows The Seeds. Weird name, and I'll see if I can dig up anything about it. Doesn't ring a bell."

The Captain squares her shoulders a little more. "Well, we're desperate, but not stupid. Don't dock us yet, and prep the least damaged shuttle. We'll try to find an undamaged umbilical, and send a team to check it out. Order of operations is life support and food. We can't fix anything if we're gasping and starving. Then it's repairs and refits. We have no idea how old this is, so we'll probably have to improvise. Then Jump fuel. I'm sure none of you want to go in cryo for the next however-many years while we putter through realspace hoping someone finds us."

"Oh, and anything you can do to find out what happened to this thing would be good. Whatever left this thing floating, we don't want the same. Plus there's got to be valuable salvage on a boat that size, might help us recoup our losses. Might even be a payday." The captain turns to the first officer.

"Assemble an away team."

The ship was in...bad shape. Not only was it damaged, due to a freak combination of a plant with a life-cycle similar to Toxoplasma gondii interacting strangely with an obscure industrial fertilizer, and tended by weird agricultural cultists, it was also an infected war-zone. The Plant's infection came in two strains, coded Pure and Fertile. The Pure strain showed no external symptoms, and only amped up the cultists already skewed thinking, causing them to be fiercely protective of The Blessed Growth. The Fertile strain caused terrible plant mutations in people. The two strains had split into factions, each believing the other to be heretical.

There was also the Crew, a group of criminals who had been hired on to this hell-ship, no questions asked, and actually knew how to operate it. BOTH cultists hate them, because their captain killed their prophet, who was attempting to force a disastrous jump in a misguided attempt to find their New Eden. They had cut their decks off from the cultists, and protected themselves with an army of androids, turned into killers.

Also, the MEGAGOAT, a horribly mutated goat the size of an industrial van, with horrible pus-filled cysts filled with flammable and corrosive stuff.

I like the MEGAGOAT.

The game ran for 9 sessions in total. Stylistically, it was largely a sandbox. I had the layout of the ship, I knew what was fucked up about each area of it, who key individuals were and what they wanted, and basically let the players loose.

The whole thing was a bit of a bottle scenario, but with the option to return to the Mothership to rest, heal, drop supplies, swap out party members, etc (although circumstances could make that easier or harder depending on the situation). This worked, but near the end, the more time they spent on and around the ship, the more they learned, and the closer they got to achieving their goals, the less horrific it became. This isn't a bad thing, just an admission that an extended bottle horror scenario doesn't have a super long shelf life. In the event of a future Mothership campaign, I would probably make traveling through more space, and seeing new and different types of horrible weird space shit, rather than extended submersion in one type of horror.

Mothership was ABSOLUTELY the right system for this sort of thing. It builds in a lot of assumptions, and they're core to the system. Characters are fragile, and can die easily, and this is ok and expected. Stress figures prominently, and you'll need to look after your mental condition as well as your physical condition. Space is weird and dangerous. It all works pretty snappily.

I made relational maps for this game. Not to scale in any way, but for my (and the players') reference as far as what connected to what, how to get from A to B, etc. My own ship reference was a flow chart.

For player-facing ones, I used a program called playscii to make CRT-flavored maps, and these were good things the players could pull off computer terminals and work with.

I also made use of item cards, something I started doing when I ran Deep Carbon Observatory, and which is a great, tactile way to go "who has what item". I could have made more use of them, but they worked well enough.

I feel like one thing I could have done better, was to give individuals ON the ship more character. I think I did alright establishing the atmosphere and character of the dread ship itself, but I could have done better with key players, like members of the cult factions, crew, and so forth. I feel like I could have made some interactions more effective, or more fun.

Something I'm going to do more of in future is build my own random tables. Things like, this guy needs a name, I need some weird features for this room or corridor, this person needs a weird mutation, I need graffiti for this wall, I need a complication for this situation. Not necessarily to use them all the time, but I think going through that ahead of time will prep my brain to work better on the fly.

Anyway, people said they had fun, and I had fun running it. Give Mothership a look for all your space horror needs, it works damn well for them.