Comfort
Comfort has two meanings in Rimworld:
- Colonists have a need for comfort, which influences their mood.
- Furniture has a property (stat) called comfort; using the furniture fills the comfort need.
Comfort need
The comfort need is satisfied by sitting in or resting on comfortable furniture.
The comfort need mechanic is similar to the "rest" and "beauty" mechanics: the comfort need bar of a pawn grows while they are using comfortable furniture, and slowly decays otherwise.
Depending on the (furniture) comfort stat, a certain maximum level of the (colonist) comfort need can be obtained. The maximum possible comfort level is the comfort stat of the furniture item in percent, capped at 100% (eg. a bed with 0.75 comfort can raise the comfort need gauge to at most 75%). When the comfortable situation ends, the need level will gradually revert back to 0%.
Comfort levels of 60% or higher give increasingly beneficial mood thoughts, starting at "Comfortable +6". A particularly low comfort level of less than 10% incurs the "Uncomfortable -3" thought and mood penalty. This usually only occurs when the pawn had to sleep on the ground without even a sleeping spot. It is, however, unrelated to the "Slept on ground -4" negative mood effect (which would also occur in this situation).
In most situations, the dominating source of "comfort" for a colonist is sleeping in a bed. Even a simple sleeping spot provides 0.4 of comfort and would leave the pawn at 40% of comfort need after sleeping on it for a few hours.
To obtain comfort need gains, the pawn has to be actually "using" the piece of furniture, such as doing work on a workbench with a chair, or actively resting in a bed. It is not sufficient to be merely standing or lying on top of the furniture.
Furniture stat
Every piece of furniture has a comfort stat, listed in the item's information panel. The comfort stat is determined by the base value for the item, the item's quality level, and sometimes other nearby pieces of furniture providing an "offset" to the base value.
Example: a bed of "normal" quality has a base value of 0.75, that can be modified with an adjacent end table by +0.05, as well as a nearby dresser by another +0.05, yielding an effective comfort stat for this bed of 0.85.
Furniture of normal quality has the following comfort stat values:
(Animal beds and sleeping boxes have no effect, despite having a comfort stat, because animals do not have a comfort need that could be satisfied. Currently the animal furniture merely marks a spot for animals to sleep or rest on, unless mods are used that enhance this behavior.)
Strategy
tl;dr: Use your best armchair for your research bench, not your TV viewing corner.
This section is only concerned with the raw effectiveness of comfort with regards to colonist mood, as there are no other comfort related effects in the game. We completely ignore the decor, beauty or role-playing value of furniture in this discussion.
The value of the comfort stat is governed by two facts:
- Comfort need falls rather slowly over time (about 5% per hour), but rises very quickly, to the currently effective comfort stat.
- All comfort need levels between 10% and 60% are equally mood-neutral.
This means that furniture with less than 0.6 comfort has hardly any effect. Even a sleeping spot would leave the pawn at 40% comfort when beginning a workday, and it would then require about 6 hours of complete comfort starvation for the negative mood effect to appear. In actual games, this is both quite rare and not very impactful. It also means that long-term use of furniture drowns out comfort effects that occured earlier.
Especially stools in front of workbenches are almost useless, because all they do is keep the comfort level at 50%. However, a pawn who slept in a bed even of poor quality runs a rather low risk of dropping to 10% comfort level regardless if stools are used or not. Do not bother crafting stools for workbenches, use dining chairs right away. Stools still make sense for a cheap eating setup, because colonists can only eat from a table if they have a seat.
In other cases, the comfort stat of furniture is impactful only if the furniture is used for non-trivial durations – this is mainly the case for all kinds of beds as well as work station chairs that are used intensively (eg. in front of research benches and certain crafting stations).
Beds are always used for extended durations, so their comfort stat matters.
Seating furniture, such as high quality chairs and armchairs, should be put in front of heavily used workstations, and not in places where this might be more intuitive like the "comfy TV section" in your recreation hall, for example. This, of course, ignores the role-playing aspect and beauty impact of these structures entirely. "Recreation furniture" is also less effective because the colonist usually goes to sleep after recreation time in a typical colony schedule, which completely drowns out any positive effect from recreation furniture.