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Working a design for fatigue in STA

Hello all!

I am writing an adventure for STA and one important aspect of the overall design is to impart a sense of time pressure. The PCs will have to be solving mysteries while being stalked by an invisible adversary while stranded on a space station. Pretty classic. They will need to perform task checks, extended work tracks, and other actions within a certain amount of time before it runs out and calamity strikes the station.

Since this is being run on the “clock” as it were, the PCs will need to be utilizing their time wisely. With the day/night cycles programmed to keep everyone on a normal biorhythm at the station, the PCs can, if they wish, “push themselves” to keep working problems throughout the night. With that possibility I wanted to design a Fatigue system. I took ideas from the Conan Fatigue design and gave it a little twist. I didn’t see something in the books I have, and I did search these forums for some other ideas, if there are any I missed please point me to them.

In the meantime this is what I have so far with an example of a PC pushing themselves to “do more”. After 16 hours (8 intervals) of activity, they start to feel the effects. Below is the rule text followed by an example chart.

Note: A cycle = 12 intervals (1 standard day), 1 interval = 2 standard hours.

Humans, Andorians, Klingons, etc: For every interval after being active for 8 intervals, Fatigue points are gained cumulatively and increase linearly for successive intervals of activity. For example, interval 9: +1 point, interval 10: +2 points (total 3 points), etc. Each Fatigue point reduces Stress by 1. When Stress is reduced to 0, the PC is exhausted beyond any ability to continue and is incapacitated for that interval and must subsequently Rest.

Denobulan PCs can ignore the effects of Fatigue for adventure purposes unless their hibernation cycle Is part of the plot. Vulcan PCs can ignore Fatigue effects for up to 14 cycles.

For every 3 Fatigue points gained, Control, Insight, Reason and Fitness are -1 to a minimum of 7 (In my mind these are the attributes that would be affected by Fatigue; dulling the PCs capabilities, I refer to these collectively as the “attributes”).

For every interval spent resting (can be sleep or inactivity, species dependent/GM decision), Fatigue points are recovered increasing linearly for each interval of Rest. After 1 interval of Rest, Fatigue gain is reset, any Fatigue points accumulated and attribute effects remain. After 4 intervals of continuous rest, all Fatigue points are recovered and attributes return to normal.

For example, a PC starts a cycle fully rested with no fatigue. The PC is active for 8 intervals then pushes themselves for another 4 intervals gaining 10 Fatigue points and their attributes are reduced by 3. Their Stress is reduced by 10 (Stress reduction tracks Fatigue). The PC then has two intervals of uninterrupted rest recovering 3 Fatigue points bringing Fatigue down to 7, (Stress regains 3 points, remember Stress loss tracks Fatigue gain) and the reduced attributes gain back 1 to a -2 penalty. The players decides they need to back into the action and decides to have the PC return to activity. At the end of their first interval they suffer 1 Fatigue point (bringing Fatigue to 8). The PC continues to push for another 2 intervals, suffering an additional 5 Fatigue points (13 total), and their Stress level and attributes take a pummeling: they are incapacitated for the next interval. They’ve been going for 32 hours with only 4 hours of rest! After the Incapacitation interval the player decides their character will Rest for the full 4 intervals to recover completely; ready for new adventures.

I am sure there are flaws here and other ways to design this. Species play a significant part to how fatigue would be modeled so I made those exceptions for a couple. What do you think?

I appreciate the work and thought you put in this!

So the fact that you are reducing Attributes is essentially the same thing as using Traits (they would increase the Difficulty instead). Personally, I would use Traits instead because it is an existing mechanic.

You reduce maximum Stress like in Conan. That is of course OK, although I feel that it does not have the desired effect in STA since it is usually less combat-intensive. So having less maximum Stress may not matter in most cases. I would actually say the characters suffer cumulative 1[CD] Stress, and Stress does not regenerate after the Scene. I think actually having suffered X amount of Stress may feel more impactful than just having less maximum Stress.

Also, while reducing Attributes essentially increases the Difficulty on Tasks, I would increase the Complication Range as well. Because when sleep-deprived, a danger is not merely failing at a Task but causing critical errors (i.e. Complications).

One other aspect for me would be to let the characters roll if they are effected by fatigue. The roll becomes progressively harder, but it has the upside that the players are more connected to the situation and actually feel that their character can push through the exhaustion, and they have to strategically decide how they would like to spend their Momentum. Further, you can easily incorporate Traits from species that don’t need as much sleep or even need more sleep, by modifying the Difficulty of the roll.

So in summary:

After 8 intervals:

  • At 9th interval: Character must make D2 Fitness + Command/Medicine Task or suffer 1[CD] of Stress and gains the Fatigued Trait.
  • At 10th interval: Character must make D3 Fitness + Command/Medicine Task or suffer 2[CD] of Stress and gains the Fatigued Trait. If already Fatigued, increase it by 1 level.
  • [Mathematically] At (8+n)th interval: Character must make D(1+n) Fitness + Medicine Task or suffer n[CD] of Stress and gains n levels of the Fatigued Trait. If the character already has 3 levels of Fatigue, they collapse of exhaustion.


  • Fatigued X: Increases Difficulty and Complication Range of all Tasks by X. Stress does not regenerate between Scenes.

I would go with using Traits and raising the Complication range to model fatigue in STA.
It need not to be so overly detailled and complicated. That works well for more detailed 2d20-based games like Infinity, but not for the more coarse-grained approach in STA.

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I was trying to get a Task Check idea together for this but didn’t like what I was coming up with @Shran. I like your approach there.

The Trait idea has a lot of merit and it goes along with STA and increase of Complication range, sweet idea!

Thanks folks for the feedback!

I have updated my design based on the great feedback here. I have discarded two big aspects: Stress reduction and a fixed upper limit to Exhaustion. I have added the Trait mechanic and used the possibility of Complication generation to drive the GM/players decision on when Exhaustion occurs. I also have made the start of Fatigue align with a characters Fitness score. I added the Task Check requirement aligned with how much the character pushes past their physical limits, with failure amping up the Fatigue Trait. Finally, I added a Trait to reflect Exhaustion and tied it to Rest.

For my design purposes I felt that having all Task Checks increase in Difficulty while a character is in Fatigue was too harsh. Given an interval is two hours, that can end up being a lot of penalty. So, I retained the attribute affects but made them apply to all attributes for simplicities sake.

Thanks to @Shran for the ideas!

Rule Text:

For purposes of determining the effects of Fatigue on Characters, they are either performing activity: awake and actively executing tasks and actions, or resting. The concept of resting varies by species but for simplicities sake, resting is when the characters are not performing any actions. For humans (and most humanoids), sleep certainly best satisfies the concept of resting.

Characters under normal conditions can engage in activity without suffering deleterious effects for a number of intervals equal to their Fitness. Denobulan characters can ignore the effects of Fatigue for adventure purposes unless their hibernation cycle Is part of the plot. Vulcan characters can ignore Fatigue effects for up to 14 cycles.

When a character has spent continuous intervals in activity without any rest equal to their Fitness score, they gain the Trait Fatigue 1. For each interval they push beyond, they must make a Command+Fitness Task Check with Difficulty equal to the number of intervals they are continuing activity. Failure of this check increases their Fatigue level by 1.

All Task Checks and Actions performed while a character is suffering from Fatigue, will have the negative effects of the Trait applied to those checks and actions.

For each interval a character rests, any Fatigue they are suffering is reduced by 1. When Fatigue drops to zero the character is considered Fully Rested.

A typical Complication that a character will suffer while under the effects of Fatigue is the Exhaustion Trait.

Trait Fatigue X: The character’s attributes are -X and Complication range for Task Checks is +X
Trait Exhaustion: The character is incapacitated and must begin Rest immediately. Fatigue recovery begins on the next interval. The character can no longer voluntarily end Rest until Fully Rested.

Here’s our example Klingon with the above applied.

While I like the approach very much (kudos, @szaccardi!), I want to propose an even more streamlined approach that discards the new track (cycles) and relies heavily on traits.

Instead of being automatically added due to long activity, the fatigued trait is added by the GM, either initially to a scene (when it’s appropriate) or due to a complication / succeed at costs / via the use of Threat. Of course, the GM has to be responsible with this.

Trait: Fatigued X
The character is exhausted almost to their limits and desperately needs rest. Their attributes are considered X points lower than they actually are and the complication range for Task Checks is increased by X. However, the character can push themselves to ignore these effects for the remainder of the scene by the following means: A successful Fitness + Medicine check with a difficulty of 1 + X by the character themselves, a successful Reason + Medicine check with a difficulty of 0 by any character that uses a stimulating hypospray (which might have opportuniy and/or escalation cost), or spending two Momentum. Spending Momentum in this case, will not remove the trait, but only its effects and only for the remainder of the scene. Spending one point of Determination, however, will allow the character to ignore the effects of this trait for the remainder of the mission. However, Determination can only used once per mission in this way and ignoring the signals of one’s own body is generally frowned upon.
Pushing themselves comes with a cost, though: Every time a character pushes themselves, the character suffers damage, rolled with an amount of challenge dice equal to X. Characters with incredibly high fitness ratings and/or of especially species especially resilient to exhaustion (like Denobulans or Vulcans) may, by the GM’s discretion have the opportunity to obtain one or two resistance dice with Momentum as if they were creating an opportunity (p. 85). If any effect is rolled, X is immediately increased by one.
If the character rests for the duration of a scene, X is reduced by one, removing the trait if reduced to zero. In most cases, the trait will be removed between missions. However, if there is not enough time to remove or even reduce the trait (e.g. if the next mission starts immediately withouth any downtime in between missions) the character might start the next mission fatigued.

Trait: Restful
This trait can be added to any scene and/or location that provides amenities and means to rest or recreate. Examples can be any recreative holodeck programme or “pleasure planets” like Risa. If a character spends a scene resting while present within the scene and/or location, they can recover from fatigue more easily. For any scene the character rests, instead of the normal 1, reduce the fatigued X trait of the character by 2.

Trait: Exhausted X
The character suffers from (long-term) exhaustion. They start every adventure with the trait Fatigued X, X equaling the rating of their exhausted trait, following the rules of fatigue as normal. However, even if they end the mission without any fatigue trait, Exhausted X stays in effect until removed by extensive shore leave (equalling a mission wherein the character cannot be present). However, if the character ends the adventure with a fatigued rating greater than their exhausted rating, they increse exhausted by one.

Introducing Fatigue:
As written above, the trait can be added by the normal means. However, to not surprise players with the effect of fatigue, GMs can also choose to introduce a Fatigued 0 trait to a character as a complication. This represents the character being tired and on the verge of fatigue, but not yet affected by any detrimental effects. At the end of the scene, they can choose to rest, not using the character for the next scene and removing the trait, or starting the next scene with the trait Fatigued 1 with the rules stated above.

Long term effects:
If a character is fatigued during a mission but recovers during the mission or ends the mission with Fatigued 1, nothing will happen.
However, if they end the mission with Fatigued 2 (or higher), the GM may choose to exchange their temporary fatigued trait with the permanent Exhausted trait (usually at 1). This should, however, only be done when characters tend to end missions with high fatigue-ratings on a regular basis.
If characters regularly use hyposprays, they can become addicted, either by receiving a special kind of an exhausted trait that cannot be removed by rest alone but that has to be accompanied by therapy, or using the advice on Trauma within the Science Division supplement.
Finally, using a point of determination to ignore fatigue for the whole mission can be seen as reckless – adding a negative effect on the reputation roll at the end of the adventure.

I feel that this is a bit more in line of the drama-focused approach of STA:

  • everything is done by a set of traits
  • there’s almost no book-keeping (and none apart of noting traits and ratings)
  • the player can always choose to stay active in play at not-too-high costs
  • long term effects spark more drama

A scene based approach like what you have there @MisterX is definitely something more STA-esque than my time based approach. Lots of drama! I actually don’t know yet how this time based approach will play out yet, (play testing upcoming). Unless there is a driving reason to use time as a resource in the adventure (as there is in my station time-boxed imminent-destruction, scenario), I think your scene based approach is more in the spirit.

Determination is something I was turning over too. Perhaps spending a Determination point to completely remove Fatigue effects can be permitted with as you note, consequences… I think I will let this be open ended for now and see what the players come up with during play testing.

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Cool idea for those that want a crunchier STA. But that’s just more than I want to track.

Maybe instead of tracking your activities, you could track your sleep instead. That’s for example how Savage Worlds does it.

It assumes that each person needs a certain amount of sleet per cycle (usually 6 hours every 24 hours). For each cycle you forgo sleep, you make a roll with increasing difficulty. On a failed roll, you get one level of fatigue.

This is simpler and you only need to track whether or not you slept in a day, but of course it does not cover details like power naps that were possible with your original system.

Also, I find it weird that you decrease attributes. This is not a common mechanic. Just increase the difficulty of all Tasks, which is what Traits do. The effect is the same. And theoretically, if you decrease attributes, you need to recalculate Stress.


Not wanting to criticise, because your solution is absolutely correct, but changing attribute values is not the same as modifying difficulty. The former affects the target numbers for the individual dice - the latter the number of successes needed to succeed on the Task roll. Mechanically and probabilistically, they are very different!

I’m not really following the details of this discussion (I agree the proposed rules are a little complex), but I definitely think it would be more in keeping to use temporary Traits (as in Fatigued X) and modify either or both difficulties and complication ranges accordingly. I particularly like the complication part, because it reflects that tired people may get the job done, but will make more mistakes.


Fair point. I should clarify my trait to only “virtually decrease” attributes regarding tasks. :slight_smile:

Nope. I concede that reducing attributes is not a common mechanic. But. First, imho, traits can do virtually everything. And second, reducing the attribute is not the same as increasing the diffculty.

Take a) a standard roll of difficulty two against a target number of 12 (no foci). Now we look at this roll with b) a difficulty increased by one and c) the corresponding attribute decreased by one.

a) difficulty two against 12, two dice
We got 2d20 and have to roll 12 or below with both of them to succeed. Alternatively, we can score a critical hit (1) on only one of them. The chance to succeed equals 40%.

b) difficulty three against 12, two dice
We got 2d20 and have to roll 12 or below with one of them and 1 (critical for two successes) with the other. The chance to succeed is 3%.

c) difficulty two against 11, two dice
We got 2d20 and have to roll 11 or below with both om them to succeed. Alternatively, we can score a critical hit (1) on only one of them. The chance to succeed is 34.75%.

Thus, increasing the difficulty instead of decreasing an attribute (thus decreasing the target number) hits the players by more than a magnitude harder.

(Edit: I wrote this post yesterday but failed to upload it. Uploaded it now and only afterwards realised that @Astronut was faster than me. Well. :slight_smile: )

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@Astronut and @MisterX are correct. Reducing attributes and increasing difficulty is not the same.

I still think reducing attributes is weird. @MisterX, the problem with your example calculation is that it is oversimplified. While I of course get the intent, it blows the differences out of proportion. You usually have a lot of tools at your disposal (Talents, Momentum, assists, …) to manage higher difficulties. That’s why a D3 Task’s chance to succeed is way higher than 3% in actual play.

Another argument against attribute decrease may be that 3rd party platforms may have a harder time to incorporate such mechanics. I play mostly online now, and it can be difficult to implement custom mechanics. Difficulty increase is the norm, so that should work fine.

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It seems like there’s an overarching issue here that I will phrase in the form of a question: “How do I make tasks a little harder in STA?”

As has been pointed out, the difference between a -1 on a roll and a jump from Difficulty 2 to Difficulty 3 are mathematically very different. I’m curious how various people handle it - seems like some folks are saying “That’s what Complications are for,” and others are saying “Just use Difficulty - if they really want to succeed, they’ll burn Momentum and Determination.”

I also feel like it’s worth asking what the feel you’re looking for is: “Characters are tired, so they fail hard,” as opposed to “Characters are tired, so they make mistakes.” Which feel you’re going for may inform your choice of mechanics.

Me, if I were inclined to get mechanics involved, I’d probably go for Complications. Err on the side of characters succeeding and moving towards their goals, but ratchet up the problems in play as their fatigue causes more and more mistakes; if disaster comes, it will be by a thousand cuts, and it’ll be obvious why (namely, they kept pushing while tired). It’s also a simpler mechanic. Additionally, if the goal is really “time pressure,” then there’s nothing saying those Complications can’t be “it took longer than you wanted” and burn more of that precious time. (At least, there’s nothing that I’m aware of that says that; I will admit, the long-task rules puzzle me and I haven’t fully wrapped my brain around them.) My second mechanical idea that seems to exist within the system as designed would be that tired characters start rolling increasing numbers of Challenge Dice as they get more tired, and if Effects pop up, those are bad.

That said, I’m a big believer in “success at a price.” Especially when the failure conditions are often things like “the ship blows up” or “everyone in the colony dies.” Other GMs and tables might believe more strongly that without dice chaos, games aren’t fun, or without regular visits from death and catastrophe, there isn’t sufficient tension at the table.

That said, good discussion here; working on ways to crank up that dramatic tension whether by mechanics or GMing technique is time well spent, IMO!


You really do not need special rules for fatigue. The GM has Threat which he can use to simulate such things a fatigue. Were STA not a narrative but a simulative RPG then it would have special rules for fatigue.


Hello again everyone! This has been a great discussion thread on this topic. Thanks for all of the contributions here. I’ve got a brief update for you on how I ended up handling fatigue in the mission.

Reducing Attributes turned out to be not only weird as @Shran mentioned, but also fiddely and pushing against the spirit of the 2d20 system a bit too far. While it is obviously doable for a GM to implement, after a few sessions I dropped the idea. I felt it was overly burdensome and didn’t add to the time-pressure, fatigue-induced-mistakes feeling I was going for.

Here’s the final approach I used throughout the remainder of the mission. Changes made:

  • Made some clarifying text changes
  • Removed all rules associated with fatigue recovery and Rested state
  • Rewrote Fatigue and Exhaustion Traits

STA Fatigue Concept

For purposes of determining the effects of Fatigue on Characters, they are either performing activity: awake and actively executing tasks and actions, or at rest. The concept of resting varies by species but for simplicities sake, resting is when the characters are not performing any actions.

Characters under normal conditions can engage in activity without suffering deleterious effects for a number of intervals equal to their Fitness. Vulcan and Denobulan characters can ignore the effects of Fatigue for adventure purposes unless extenuating circumstances are part of the adventure plot (Denobulan hibernation cycle, etc.)

The time length of an interval is adjudicated by the GM and can vary from standard hours for normal shipboard activities, to shorter timeframes for intense activity such as prolonged conflict, running, or other physically taxing situations. In this way, even species normally immune to sleep deprivation fatigue, can be affected by a Fatigue trait due to physical exertion. The concept of intervals remains loose, just as in the Timed Challenge and Extended Task rules.

When a character has spent continuous intervals in activity without any rest equal to their Fitness score, they gain the trait Fatigue 1. This is the rules applied with a sleep deprivation twist. Alternatively, the Fatigue trait can be applied via a Complication due to physical fatigue.

Any Task Checks and Actions performed while a character is suffering from Fatigue, will have the negative effects of the Trait applied to those checks and actions.

Trait Fatigue X : Complication range for all Task Checks is +X. Once the Fatigue trait is applied to an organic being, it increases by +1 for each subsequent Task Check performed.

Trait Exhaustion : The character is incapacitated and can no longer take Actions.

A Create Advantage can remove Fatigue or Exhaustion traits as per core rules (momentum spend), and I took any narrative element created by the players to accommodate it. For example, use of adrenaline hypo-sprays etc. The GM can determine how much of these remediations will work from the players and can rule that they are no longer effective. “One more adrenaline shot and Lt. McGrath is going into cardiac arrest Chris…”

I found it to be a nice way for me to spend threat once the characters had really pushed themselves. For example, in the adventure I was running, an entire day had gone by while the characters were frantically working to handle a viral outbreak while the space station they were on was in a decaying orbit. Good times.

The increase in Complication Range as the characters grew more fatigued added to the feeling that mistakes could be made. Once the Fatigue level got high enough, a typical use of a new Complication was to throw Exhaustion on the character.

Ok there you have it, my current incarnation of fatigue in STA. I hope this has inspired some thoughts on this subject, its been fun for me and my players. LLAP!

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Wow, great you share your experience! And thanks for sharing your improvements on all of our suggestions!

I’m still not sure on a fixed interval-approach, but, then again, it compensates the effect of scenes that are loooong with lots of action yet technically only count as one scene.

But there’s one thing I’m wondering: Once acquired, the fatigue trait will rapidly explode under this system, won’t it? One would enter combat with Fatigue 1 and leave it with Fatigue 4 or 5. That seems a bit harsh to me – I would be very interested in your experience with your players! Will they quickly remove the complication with Momentum spends etc.?

Another thing: When Exhaustion is designed to incapacitate players – where’s the difference to injuries? Especially when fatigue is designed to pile up quickly, one could simply rule that it caps at Fatigue 5 (since max complication range equals five) and any surplus will lead to a (non-lethal) injury.

Thanks for the points @MisterX, all very good ones.

As designed right now, you are correct, the fatigue level (if already fatigued) will explode during intense Task Check attempts unless mitigated somehow. A player can spend 2 momentum to cancel an increase (as in Create Advantage). When I had a couple of the characters running a fight against the adventure “boss”, phaser beams were flying and the momentum pool was topped off and lots of dice were being added to the ranged attack task check pools (very annoying for the GM).

Narratively, an intense fight like that should be exhausting, particularly if the character is going into it already tired. The “model” of increasing fatigue worked well in that the Complication range in the combat could get maxed out reflecting that characters were now more mistake prone. They had the opportunity to mitigate these affects by spending momentum, and having that extra moderation on the momentum pool made the fight a little more challenging. This is just one approach to manage that increasing level of fatigue. Alternatively, that '+1" per task check could be changed to “GM decides”. We are all powerful right? Right?

Your point about Exhaustion is correct as well, It’s effectively equivalent to 0 Stress without getting phasered or clonked on the head to get there. I think its more of a narrative tool to take someone out of the fight if the situation makes logical sense, and they won’t be in the lethal injury range and other negative things that can happen from 0 Stress. Plus, they could also attempt to cancel Exhaustion with a momentum spend as well.

“Lt. McGrath was spent, exhausted beyond all measures of human endurance, but through pure force of will he called upon an inner reserve of energy and in one final attempt, swung his makeshift bludgeon to bring down the charging beast.”

One of my players always spends an opportunity cost to find a big honking piece of metal to use on my NPCs. Very annoying. You know who you are!

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If my team is tired I usually add a trait that increase complication range. Singe, you’re tired you are more prone to make mistakes. Increasing complication range is my team worst nightmare.
Fatigue can be cured with a doctor that creates advantage (to remove trait)