Rest

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Rest is the game mechanic that controls Characters' needs for sleep. A character with a higher rest value has slept recently, and is less tired than another character with a low rest level.

Levels of Rest

Characters' rest level is grouped into four thresholds: Rested, Tired, Very Tired, and Exhausted. Each threshold exhibits different effects on a character, especially their Thoughts. When a character's rest level is zero they may collapse from exhaustion; they will immediately begin sleeping on the ground wherever they are.

The rest levels are as follows:

Label Rest Mood Debuff
Rested >= 28% None
Drowsy >=14% and <28% −6
Tired >=1% and <14% −12
Exhausted <=1% −18

Rest caps at 0% and 100%.

Rest Changes

Negative

When awake, rest goes down every 150 ticks (1/400 of a game day) depending on the character's current rest.

Threshold range Rest change per 150 ticks Rest change per game day Real time in state[1] Game time in state[2] Real time since 100% rest[3] Game time since 100% rest[4]
Rested 100% - 28% 0.237% 95% 45,474 ticks (12.63 mins) 18.189 hours 0 ticks (0 secs) 0 hours
Drowsy 28% - 14% 0.166% 66% 12,632 ticks (3.51 mins) 5.053 hours 45,474 ticks (12.63 mins) 18.189 hours
Tired 14% - 1% 0.071% 28% 27,368 ticks (7.6 mins) 10.947 hours 58,105 ticks (16.14 mins) 23.242 hours
Exhausted 1% - 0% 0.142% 57% - - 85,474 ticks (23.74 mins) 34.189 hours
  1. Real time spent in the state before crossing the lower threshold, assuming no rest is gained
  2. Game time spent in the state before crossing the lower threshold, assuming no rest is gained
  3. Real time spent before entering the state, assuming no rest is gained and the starting rest is 100%
  4. Game time spent before entering the state, assuming no rest is gained and the starting rest is 100%

Positive

When a character rests in a bed, their Rest value increases over time. At 100% Rest Effectiveness and 100% Rest Rate Multiplier, a character requires 10.5 hours (26,250 ticks) to full rest from 0% to 100%.

 Every 150 ticks (2.5 seconds at 1x speed), rest increases by 100% * (Ticks in interval (150) / Ticks Per Game Day (60000)) * (Hours per day (24) / Sleep Hours for Full (10.5)) * Rest Effectiveness * Rest Rate Multiplier
 = 100% * (150 * 24) / (60000 * 10.5) * Rest Effectiveness * Rest Rate Multiplier
 = (100%/175) * Rest Effectiveness * Rest Rate Multiplier
 = ~0.57143% * Rest Effectiveness * Rest Rate Multiplier

175 of these 150-tick intervals is the 26,250 ticks (10.5 in-game hours) required to fully rest from 0%.

Multipliers

Rest Rate Multiplier is a character (pawn) stat that defaults at 1.0 and is based off blood pumping, metabolism, and breathing capacities (and thus is affected by relevant injuries, bionics, etc.)

  • Blood Pumping has a .3 weight
  • Metabolism has a .3 weight
  • Breathing has a .3 weight

Rest Effectiveness depends on the object the character is sleeping on:

Object Rest Effectiveness at Normal quality Rest increase per 150 ticks Rest increase per full 24-hour game day
Sleeping Spot or Ground 0.8 ~0.45714% ~182.857%
Bedroll 0.95 ~0.54286% ~217.143%
Bed 1.0 ~0.57143% ~228.571%
Royal Bed 1.05 0.6% 240%

and the quality of that object:

Quality Rest Effectiveness Multiplier
Awful 0.86
Poor 0.92
Normal 1.0
Good 1.08
Excellent 1.14
Masterwork 1.25
Legendary 1.6

Therefore, when a character with 100% Rest Rate Multiplier reaches the Tired threshold (28%), it takes them this long to return to full (100%) rest:

Object Ticks to Full Rest Hours to Full Rest % of Day to Full Rest
Sleeping Spot / Ground (0.8) 23,625 ‭9.45 39.375%
Normal Bed (1.0) 18,900 7.56 31.5%
Legendary Royal Bed (1.05 * 1.6 = 1.68) 11,250 4.5 18.75%

Analysis

There exists a balance point for every type/quality of bed (and character, if that character has offsets to Rest Rate Multiplier or Rest Fall Rate), in which the hours spent sleeping and the hours spent awake during a 24-hour period precisely balance. This is ultimately a piecewise equation, as the rest fall rate is piecewise based on the current rest level (see above). We can ignore the Exhausted category, as a character must spend >24 hours awake (if starting at 100% rest) before reaching that threshold.

As long as the character is awake for less than 18.189 hours per day, however, this is a single-part equation, as the character will never reach Tired. The percentage of the day that the character may stay awake, expressed as a decimal value, with a given RestMult (equal to Rest Effectiveness * Rest Rate Multiplier) is reached by solving the following equation for %DayAwake:

 0.95 * %DayAwake = (1 - %DayAwake) * (24/10.5) * RestMult

This gives the following equation:

 %DayAwake = (320 * RestMult) / (320 * RestMult + 133)

At 1.0 RestMult (normal unmodified character in a normal quality regular bed), this gives a value of 70.64% of the day awake, or ~16.95 hours. Higher RestMults will grant more hours per day awake per this equation, up to 18.189 hours (75.789% of the day) awake.

Beyond that point, we need a piecewise equation. The RestMult needed to be awake for 18.189 hours per day (0.75789 %DayAwake) is 1.301, which can be achieved with only a masterwork Royal Bed. After this point, we can use a fixed value for the ~75% of the day awake before hitting Tired, which results in a 72% drop in rest, and then compute the remainder of the time awake off of the rest fall rate when Tired (66.5% per day rather than 95% per day). This can be found by solving:

 0.72 + (%DayAwake - (0.72/0.95))*0.665 = (1 - %DayAwake) * (24/10.5) * RestMult

This gives:

 %DayAwake = (16000*RestMult - 1512) / (16000*RestMult + 4655)

At 1.3125 RestMult (an unmodified character in a masterwork Royal Bed), which is just past the threshold where this equation is needed, this gives a value of 75.962% 0f the day awake, or 18.231 hours.

At 1.68 Rest Effectiveness (the legendary quality Royal Bed in the table above) and a character with the Quick Sleeper trait (50% Rest Rate Multiplier), a Bionic Heart (+25% Blood Pumping = 7.5% Rest Rate Multiplier), and a Bionic or Royalty stomach (all of which are +25% part efficiency -> +12.5% Metabolism -> 3.75% Rest Rate Multiplier), for a net of 1.5*1.075*1.0375 = 1.673 Rest Rate Multiplier, the RestMult = 1.68 * 1.673 = 2.811. At that level, the character can be awake for 87.573% of the day, or 21.017 hours.

In theory, there also exists a point at which the Very Tired piece of the equation becomes a factor, but this would require a pawn to be awake for at least 96.84% of the day (23.242 hours). This would require a RestMult of at least 11.915 (ie. 1191.5%), which is impossible to hit in the base game (and even with most mod setups), and thus can be ignored.

If the character is using a Circadian assistant, their rest fall rate is reduced by 20%, meaning it takes 25% longer to reach each threshold. The equations in this case must be re-derived (derivation is left as an exercise for the reader), but the simple answer is:

  • A character otherwise unmodified except for the Circadian Assistant, using a normal quality bed, can be awake for ~75.047% of the day (~18.011 hours), about 6.3% more of the day than without the implant.
  • An otherwise-unmodified character in a masterwork Royal Bed can be awake for ~79.787% of a day (~19.149 hours), about 5% more of the day.
  • The above bionically-modified Quick Sleeper pawn in a legendary quality Royal Bed, with the addition of a Circadian Assistant, could be awake for ~89.421% of a day (~21.461 hours), about 2.1% more of the day.
  • None of these characters would ever reach "Tired", which takes ~94.737% of a day, or ~22.737 hours, with a Circadian Assistant installed.

See Also

Pawn sleeping furniture:

  • Sleeping spot - a free method to designate a place to sleep, but uncomfortable with terrible rest effectivness.
  • Double sleeping spot - a sleeping spot equvialent bed that allows up to two pawns to sleep together.
  • Bedroll - a portable, lower tech version of the bed that provides less comfort and rest effectivness.
  • Double bedroll - a bedroll equvialent bed that allows up to two pawns to sleep together.
  • Double bed - a bed equvialent bed that allows up to two pawns to sleep.
  • Royal bed - an expensive double bed that provides additional comfort and rest effectiveness.
  • Hospital bed - a bed equivalent with a larger immunity gain speed factor

Animal sleeping furniture: