If you asked me to describe the combat system of Mothership in one word, it would be a toss-up between “strange” and “missing.”

What seems to have happened is that Mothership 0e had a turn-based initiative system. A decision was made at some point to transition Mothership 1e to a more freeform(?) resolution system, but the execution was pretty badly muffed. (It may have also been further complicated by a last minute attempt to revert back to the 0e version of the rules.)

The result is that the rules and examples of play contradict each other, and support material — including stat blocks and adventures — don’t seem to be in sync with the mechanics. To attempt to give a taste of what the confusion in the rulebooks looks like:

• The Violent Encounters chapter in the Player’s Survival Guide suggests a player-facing system, in which PCs make all the checks.
• The example of play is also player-facing, but doesn’t follow the same procedure.
• In the Warden’s Operations Manual, however, player-facing is described as an alternative to the normal combat system. (But, if so, what’s the normal combat system?)
• Meanwhile, all the horrors in Unconfirmed Contact Reports have Combat stats that are designed to be rolled to determine damage… except what function is that supposed to serve if the players are supposed to be making all the checks?

Sean McCoy, the designer, has said that rules-as-written is supposed to be that the monster takes a turn and rolls Combat checks, although he prefers the player-facing option “90% of the time.” And on the Mothership Discord he’s mused about how the Combat stat should be interpreted (“my guideline would be: monsters with 60+ Combat impose [-] on player facing rolls, and monsters with Combat below 20 impose [+] on player facing rolls”).

From what I can tell, the result is that there are three major options for combat in Mothership:

1. Everybody takes a turn, including the monster(s), with the monsters rolling Combat.
2. At the beginning of a round, the GM threatens Harm (to use the parlance of Apocalypse World) and that Harm (e.g., damage) is inflicted if the PCs fail to prevent it with their checks during the round.
3. Monster damage can be inflicted as a consequence for any failed roll by the players. (Possibly resulting in the monster “attacking” multiple times per round.)

This uncertainty has also led to nigh-infinite variation in actual practice, most of which can be characterized as GMs filling the howling vacuum with whatever combat procedures they can nick from other RPGs they’ve played.

(Honestly, you can even see this in my own interpretation of Mothership’s examples of play through the lens of Apocalypse World terminology.)

The most charitable interpretation of all this is that the intention is for the GM to just kind of fluidly move back and forth between these options at their whim. (Or, if you like, in accordance to their sense of “dramatic timing.”) But the difference in outcome is clearly so radically different that it becomes meaningless for the players to even pretend that they have true agency.

Of course, this also affects adventure design. When the combat system is lost in time and space, it’s impossible to actually dial in difficulty. You can arguably see this in Another Bug Hunt, the adventure bundled with the core rules, where the carcinid monsters fluctuate between “one is a nearly unstoppable killing machine” to “actually, y’all can take out a dozen of them with no problem” and than back to “oh no! there’s three of them! y’all gotta run!” (Although, again, it’s possible the intention is for the GM to just enforce whatever “vibe” the current scene has been scripted to have.)

EVERYBODY TAKES A TURN

If you go with Option #1, you’ll need to add an initiative system. Mothership 0e used Speed checks:

• Success, you go before the bad guys.
• Failure, you go after the bad guys.
• Critical Success, you get an extra action.
• Critical Failure, you can move OR take an action, but not both.

That works well enough, although you’ll need to decide whether to check each round or just once at the beginning of combat. (And, if so, how long the effects of Critical Success and Critical Failure results last.)

The advantage of this approach is that it likely cuts through all this folderol. It’s clear-cut and it will be very obvious to you which sections of the rulebook you should simply ignore.

Other simple options could include:

• Bad guys always go first.
• PCs always go first (in any order), unless Bad Guys ambush them or seize advantage with an Instinct check.
• Go around the table, with bad guys acting when it’s the Warden’s turn.
• Go around the table to resolve PC actions. The Warden can choose to have a bad guy take their turn before or after any PC’s turn.

MY EXPERIENCE AT THE TABLE

I’m a cuss-headed fellow, though, so I’ve been trying to grapple with the player-facing vision imperfectly presented in the Player’s Survival Guide, which I think can be broadly summed up as:

1. GM threatens Harm. (Again, using an Apocalypse World term of art.)
2. Players declare actions by going around the table.
3. GM makes rulings for how actions are resolved.
4. Players all roll dice (if necessary) simultaneously.

Unfortunately, after running Mothership for a few sessions, the results have not been particularly satisfying. Partly there’s been limited combat and, therefore, limited opportunities for me to experiment, but also:

First, without specificity locking things down, the system is mixing poorly with my default GM stance of letting the PCs set an agenda and then playing to see what happens when they try to make it work. I need to work on setting stronger, clearer Threats and really focus on, “Did the PCs stop the Threat? If not, devastate.”

Second, I’ve still been trying to figure out how to incorporate the Combat/Instinct stats for the critters. Having the creatures make rolls to resolve actions seems to only water down the Threats even more, so it’s not working. It’s just fundamentally problematic that the entire mechanical chassis for horrors in Mothership is incompatible with the combat procedures described in the Player’s Survival Guide.

Third, I’ve been running an open table and my players have rolled random loadouts that include Advanced Battle Dress (AP 10, DR 3) and the 1d100 DMG laser cutter. This isn’t a problem, per se, but in combination with the adventures I’ve been running — which have been slow burning explorations of creepy environments, and then GAH! CREATURE FIGHT! — I’m cognizant that this is likely warping my limited experience with Mothership combat.

Fourth, overall the fights have been thrilling and the players have been immensely enjoying them, but I’m mostly faking it with vibes and panache. This isn’t great for me as a GM because I really, really don’t like killing PCs through acts of capricious fiat. Since the whole combat system feels like a towering edifice of fiat right now, my gut instinct is making me pull my punches when it comes to lethal consequences, and in the long-term that’s really going to hamper a horror game like Mothership.

So my next step at this point is to get a little more specific in how I’m structuring this. That’ll likely give me a bit more clarity when I’m actually running the game, and if I’m at least in the ballpark I should be able to iterate through playtesting. (And, if  not, then at least I’ll know that and be able to toss all this in the burn pit and start over.)

Let’s take a peek at what I’m currently thinking.

THE THREAT SYSTEM

The core combat loop for Mothership is:

• GM makes a Threat.
• PCs declare and resolve actions.
• GM resolves Threat and sets a new Threat.

When making a Threat, the GM should default to devastating consequences.

COUNTERING THREAT: If the PCs’ actions during the round don’t counter or block the Threat, then the Threat is resolved. (You may also have situations where threat is mitigated and only some of the original Threat goes into effect.)

RESOLVING CHECKS: When the PCs fail a check, there should be consequences. Depending on circumstances, those consequences might include the creature automatically dealing damage; making a Combat check to inflict damage; or gaining the Edge (see below).

HORROR THREATS

The Threat from a horror should almost always include one automatic hit for damage. To this, add one (or more) of the following chasers:

• Special Ability: The creature gets to use its special ability (e.g., sucks blood, implants larvae, infects with lycanthropy).
• Ravage: After dealing their automatic damage to a target, the creature can make a Combat check to inflict an additional attack of damage.
• Multiple Targets: Instead of automatically damaging one target, the horror automatically hits multiple targets (e.g., it charges down a hallway smashing through or slicing up anyone within reach; tentacles burst out of the amorphous blob, hitting everyone in Close range; there are multiple creatures and they’re all hitting different targets).
• Trap: One or more PCs become trapped (e.g., the monster is pinning them to the ground; backed them into a corner; etc.).
• Environmental Complication: In addition to the horror, the PCs also need to deal with some other crisis in the environment (e.g., the hull has been punctured and air is rushing out; the blast doors are lowering, threatening to trap them with the creature; the timer on the bomb is ticking down).
• Slaughter the Innocent: The horror takes out one or more screaming bystanders or similar extras in the scene. (This shouldn’t include significant members of the supporting cast, who should be targeted like PCs.)
• Escalate: See below.

Specific creatures or situations may, of course, suggest other chasers. The list above is just a useful set of defaults.

EDGE

As an advanced option, consider the tactical position/momentum of the fight. We’ll refer to the side which currently has tactical advantage as having the Edge. By default, you can assume the horror starts with the Edge in the fight unless circumstances suggest otherwise (e.g., the PCs have managed to ambush it). Of course, in addition to blocking the horror’s Threat, the PCs may also be able to take actions that give them the Edge.

If the horror has the Edge, it can make a full Threat as described above (i.e., damage + a chaser of additional nastiness).

If the PCs have the Edge, then the horror’s Threat options, depending on circumstances, will be limited to one of the following:

• Make a Combat check in order to deal damage/use a special ability.
• Regain its Edge in the fight.
• Withdraw. (It will be back later, once again likely defaulting to having the Edge.)

For example, one of the PCs manages to pin a zombie to the floor. They now have the Edge on the zombie. Withdrawal isn’t an option (since it’s pinned to the floor), but the zombie could either try to escape the pin (regaining the Edge so that it can make a full Threat on the next turn) or try to deal damage to the character pinning them.

It may often be useful to think of the tactical Edge as a thing that has to be actively maintained by the PCs (e.g., the PC pinning the zombie to the ground has to keep making Strength checks each round to hold it down). No resting on your laurels!

Note: You don’t have to think of Edge as a super formal thing. It probably isn’t a player-known structure. (Although, for some players, knowing about it may encourage tactical creativity.) But it can be a nice mental model for the GM to have so that combats have a satisfying back-and-forth pacing and the PCs’ actions feel like they have meaningful consequences.

ESCALATION

You can expand on the binary concept of Edge by simply extending the concept in both directions.

If the horror has the Edge, it can escalate (e.g. by getting into a better position; charging up its super-weapon; summoning reinforcements; etc.). For each escalation, you can add another chaser to the Threat each round.

If the PCs have the Edge, they’re in a position to potentially

• withdraw;
• isolate the threat;
• force the horror to make its checks with disadvantage;

or otherwise prevent the horror from directly assaulting them.

You may find it useful to think of escalation in terms of vectors. For example:

• The alien can’t attack you right now because the door is blocking it. Can you stop the alien from getting through (or around) the door?
• Okay, it got through the door, so now it’s in the room with you and is threatening harm. Can you escape/kill it first/whatever?

Or:

• It’s trying to take out your tires.
• It’s taken out your tires, can you keep control of the vehicle?
• You’ve crashed and now the alien has jumped on top of the vehicle. It can easily strike anyone who gets out, and its serrated tail starts spiking down through the sheet metal and into the compartment.

A generic progression along these lines is:

• It’s trying to get to a position where it can hurt you.
• It can hurt one of you.
• It can hurt all of you.

You can also think of this in terms of setup and payoff: On the level of a single round you set things up by Threatening an outcome at the beginning of the round; then you pay off that Threat (by either fulfilling it or thwarting it) at the end of the round. Escalation just extends this same concept, with the resolution of this round’s Threat setting up an even bigger payoff (for either the PCs or their opponents) in the next round!