Hazards In Space! Adapting the Hazard Die For Mothership
Heeding the call of Ben L on Bluesky for a Mothership blogging renaissance to fill in the fruitful voids left in that game, I'm writing up this quick post to talk about the random encounter system I recently used in a session of my ongoing campaign in the playtest for my adventure for the Below A Bad Moon Jam. As a disclosure, I'll readily admit I'm far from deeply read into how folks are doing things for Mothership, so someone may have done exactly this already, and I'm sure there's many other good random encounter systems in use out there as well, but this is my small contribution nonetheless.
This is also nothing particularly innovative, as it's just riffing on the Hazard System by Brendan, which I became familiar with through how Yochai implemented it in Cairn 2e. The main change here is switching the d6 for a d100, since it just feels right to keep the dice consistent in Mothership. This does seem to be a pattern for Mothership in the adventures I've run, with Haunting of Ypsilon 14 using a simple d10 roll to determine where the monster goes and who it kills, while Gradient Descent uses a more complicated d100 roll to determine encounter chance, distance, and reaction in one based on rolling doubles, high or low, and evens or odds. To be honest, while I like the idea of it, even six sessions into Gradient Descent I still was going back to the page for it to figure out the result of my rolls each time, and it's ultimately too complex for my taste.
Apart from switching to the d100, with ~20% chance buckets for the results, there's a few other specific changes I made here. One is a change I make every time I use this system, which is to swap the "Percept/Sign" result for "Far Encounter." I like to make it more explicit that you still roll on the encounter table, you're just then placing that encounter in an adjacent space with some sign of it perceptible to the player characters. This also gives you effectively a 40% chance of an encounter each turn, which like better to keep things dynamic. Another is changing the "Loss" result to be more sci-fi specific and calling it "Equipment Failure" with battery failure or another malfunction happening.
Lastly, in the initial encounter table for this particular adventure, I've got it as a 40% chance of having the "Rest" result, because things are intended to ramp up over time, and there's a new result that comes into the 61–85 result range after a certain amount of time and introduces new environmental effects. That's actually one reason I really like this system overall is that it lets you swap in and out results easily and customize it to the adventure (I should probably make a larger post sometime about the different ways I've implemented the d6 version in the last few adventures I've published).
Without further ado, below is the system as implemented in my forthcoming adventure "Worms In Space!" which should be coming out a few days after this is posted.
Initial Random Encounter Procedure
Random Encounters
Allow 15-30 minutes of real time for player characters to become familiar with the CAS and its crew, then roll for a random named NPC or pick one who is in the room with the player characters and have worms erupt violently from their torso.
After this point, roll for a random encounter every time player characters enter a new room or if they spend more than 10 minutes of game time in a single location.
Roll 1d100:
0-20 - Close Encounter: Roll on encounter table and place encounter in room with player characters
21–40 - Far Encounter: Roll on encounter table and place in an adjacent room to player characters, visible or audible to them
41–60 - Equipment Failure: Random piece of player character equipment loses battery charge or otherwise fails
61–100 - Calm: Nothing happens, for now
Encounters
1 - 1d4 unnamed NPCs with worms wandering around
2 - A random named NPC with worms wandering around (if not seen before with worms, worms now erupt from their body)
3 - An unnamed NPC writhes on the ground and worms erupt from their body
4 - An unnamed NPC is under attack by 1d4 NPCs with worms
5 - An unnamed NPC cutting off a body part to remove the worms
6 - 1d6 unnamed NPCs with worms feasting on another unnamed NPC
Escalated Random Encounter Procedure
The MEGAWORM
After three random encounters or 1 hour of real time after starting random encounter rolls, the MEGAWORM begins its assault.
The MEGAWORM is a massive, unknowable, creature living in the moon’s core and only emerging in places around vents with tentacles that are identical to giant tube worms but much larger. It controls the cryotectonic activity and begins shaking the moon and erupting cryovolcanoes. At the same time it batters the sides of the CAS with its tentacles, shaking the entire station.
From this point on a result of 61-85 on the random encounter roll, roll for a MEGAWORM encounter. Each is accompanied by a violent shaking from tectonic activity or the MEGAWORM hitting the CAS
1 - Electrical failure in this room for 2d10 minutes
2 - Ceiling panels fall suddenly
3 - Pipe burst filling the room with toxic gas
4 - Doors become jammed in their frames.
5 - Hull breach and scalding water begins pouring in
6 - MEGAWORM tentacle breaks through hull and thrashes around while water pours in
After posting all of this I now realize I should have made the encounter tables d10 for consistency, but we're too far along in layout now for the jam deadline. Oh well...