Circadian half-cycler

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Circadian half-cycler

Circadian half-cycler

A signal redirector which isolates half of the brain, allowing the other half to sleep while the user remains outwardly awake. By alternating brain halves, the user never needs to sleep. Unfortunately, two hemispheres are better than one - working half a brain causes a reduction in consciousness.

Base Stats

Medical ItemsBody Parts
Tech Level
Market Value
1030 Silver [Note]
4 kg


Crafted At
Fabrication bench
Required Research
Circadian influence Techprint
Skill Required
Crafting 8
Work To Make
26,000 ticks (7.22 mins)
Resources to make
Plasteel 15 + Advanced component 4
Advanced, ImplantEmpireCommon
Bionic, ImplantEmpireCommon

The Circadian Half-Cycler gives a pawn that's been implanted with it the ability to never sleep again, at the cost of a permanent 15% Consciousness penalty.


Circadian half-cyclers can be crafted at a Fabrication bench once the Circadian influence research project has been completed. The required techprint can be obtained either by trade or completing quests for the Empire. They require Plasteel 15 Plasteel, Advanced component 4 Advanced component, 26,000 ticks (7.22 mins) of work, and a Crafting skill of 8.


A circadian half-cycler is installed in the brain and removes the Sleep need entirely. Consciousness is reduced by 15%, which itself reduces work-related stats like Moving and Manipulation, as well as Eating and Talking.

When a pawn with this implant is shocked with EMP, they will receive brain shock, knocking them unconscious temporarily.


Installing the part requires 2,500 ticks (41.67 secs) of work, 2x medicine of ?? quality or better, and a Medical skill of 5.

Removing the part requires 2,500 ticks (41.67 secs) of work, 1x medicine of ?? quality or better, and a Medical skill of 5.

If the operation fails, the part has a chance[What Chance?] to be destroyed.


Assuming a colonist sleeps for 8 hours, this implant allows them to work an additional ⅓ of the day, and saves space on a bedroom. Even with the consciousness loss, this makes pawns have more work time, and thus better for many tasks. This assumes you don't have many sleep reducers; see #Comparison to reducing sleep for details on that.

An unfortunate side effect of the half-cycler is mood. No sleep will prevent Lovin' entirely, remove the moodlet from an impressive bedroom, and deprive a pawn of a bed's Comfort level. An armchair can provide comfort for crafter-type pawns, but all these mood-increasers are quite significant. Non-ascetic nobles still desire a bedroom that meets their needs.


The consciousness loss has a different effect on different work types.

  • Menial, quality-less tasks like Cooking, Research, Hauling, or Cleaning are done slower, but the extra time easily makes up for it.
  • Crafters, Artists, and Constructors will produce the same-quality items, so the extra time is a net positive. Note that low-skill construction is more likely to fail.


  • Plants and Mining Yield are lowered by Consciousness, but the extra time means more things can be planted/mined.
    • Good when plant space isn't an issue, or when mining at rock.
    • Bad when plant space is limited, or when mining ores.
    • Deep drilling yield is reduced, but as it takes so much time, the half-cycler often helps anyways.


  • Social pawns and Animal handlers will perform worse, with more failed attempts and higher prices. As animals and prisoners sleep, while trade is inheriently limited, the half-cycler has little benefit.
  • Similarly, Medical pawns will tend slower, with less quality, and have less successful surgeries. Tending is a time-sensitive action, and does not need to be done constantly.
  • Combat or Hunting pawns are less accurate, will get injured more, and are slightly more likely to die by Consciousness loss.
    • EMP also becomes harder to use due to Brain Shock. It may be wiser to EMP mechanoids anyway, losing a combatant in the process.

Of course, pawns can be good at multiple work tasks. For example, a pawn that mostly does Crafting can also be your main Social pawn; independent cases should be weighed differently.


Comparison to reducing sleep

A high quality royal bed, improvements to metabolism and blood pumping such as bionic stomachs and bionic hearts, and of course the circadian assistant all affect a pawn's need for rest.

A bionic stomach and heart increase the Rest Rate Multiplier to 111%, a legendary quality royal bed provides 168% rest effectiveness, and the circadian assistant decreases rest fall rate by 20%. Thus, they can reduce the required sleep down to 43%. Luciferium further improves the rest rate multiplier to 126%, and the required sleep down to 38%. Thus, the circadian half-cycler gives the pawn approximately an 4-4.5 hours of working time compared to an optimum sleeping set up, at the expense of the consciousness penalty, the loss of impressive bedroom, comfort the loss and lovin' mood buffs. The effect of the consciousness loss means that a pawn with a half-cycler will work slower, losing work progress approximately equivalent to 2 hours compared to a regular pawn over the course of the day.

Comparison to Never Sleep

The never sleep gene will completely prevent sleep with no Consciousness loss. However, with a metabolic efficiency of -6, it requires negative genes or archite metabolism to even be used at all. It takes a large amount of negatives to negate the penalty, or archite capsules for the aformentioned metabolism gene.

Never sleep is not found in any of the default xenohumans, so a genepack must be found, both for the sleep gene and whatever you're using to compensate. Alternatively, you can start with the gene, which still comes at the genetic cost.