Skills
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Every character in RimWorld has a set of skills; these skills govern their effectiveness in the relevant tasks. A character may be unable to undertake certain work types due to backstory elements, and as such, the relevant skills will be disabled entirely, and show " - " under skills on the Bio tab. Experience points are gained by performing a relevant task or may be boosted by using a neurotrainer.
Learning skills
All skills are acquired and improved by performing their associated work types or tasks. Doing so will earn the character experience points per skill, which in turn will level up the skills. The resulting skill level then improves the performance in all associated tasks and types of work. Skills are levelled up individually, and there is no single "character level" as in many role playing games.
In some cases, special tactics can be employed to more effectively steer the skill training in the colony, especially during periods of low work in colony development. See the main article on skill training for more information.
Skills vs work types
Skills and work types (or "tasks") are two different, but related, concepts. In some cases, like "mine" (work type) and "mining" (skill), there is an almost perfect correspondence, but in many other cases there is not: the work types "tailor" and "smith", for example, are associated with the crafting skill. Some tasks listed on the work tab do not even have an associated skill (eg. "haul", "clean" and "firefight").
The Work tab, where you assign tasks to colonists, indicates which skills are relevant for a given task (by mousing over a tick box). It also shows you if the colonist has a passion for those skills (with an icon in the tick box), and if a significant proficiency has already been acquired (by emphasizing the tick box border). Lower skill pawns have their work box darker, and higher skill pawns have it lighter. Extremely proficient pawns have a golden box. When assigning work to a pawn with low skill in a certain job, the box will have a red outline. Passions appear as extremely small flames at the bottom-right hand side of the work box. All these aspects are important for deciding how to assign tasks and types of work.
In general, you want a colonist to perform tasks they are good at (it is productive for your colony), as well as tasks they are passionate for (have them improve the associated skill and also keep them happy while working).
Skill levelling in Rimworld is very similar to many role playing games: experience points are constantly earned, and the skill is levelled up when certain thresholds are reached.
Importantly, the effect of a skill improves by level, but it costs more and more XP to gain another level in a skill. This means that skill training is more effective the lower the skill level is.
As an example, consider the influence of mining skill on mining speed: 12% additional mining speed is granted (additively, and relative to a "base speed") by each skill level. However, each additional 12% costs more and more XP, which translates into more and more time spent mining. The same principle applies to many other skills, such as researching and the intellectual skill.
An exception can be made for the artisan skills: crafting (ie. smithing and tailoring), artistic and construction. A high level in these skills allows creating items of exceptional quality (excellent or better), and gives a good chance to create a legendary item when the pawn is inspired. Items get disproportionately more valuable at high quality levels. This may compensate for the lost efficiency when training a master in a skill.
When a player pawn gains a new level in a skill, a text mote will be displayed.
Too smart
Skill point acquisition strategy
The above implies that on average it is better to spread out the skill training over several colonists instead of having only one "expert", except for the artisan professions where it is usually good to have true experts in the colony.
For example, you need to acquire about 150,000 XP to make one colonist a "region-known master" (level 16); the same amount of XP would be enough to have three colonists at level 9 ("solid professional"). This avoids the risk of losing the only pawn that is capable of the task, and in most cases three level-9 workers are better than a single level-16 expert.
Decay
Furthermore, there is another mechanic in play called decay: starting at skill level 10, XP points are continuously drained away. A skill level is lost only after falling to 0 XP points and then losing a further 1000 points, preventing pawns from bouncing between levels when right around the threshold. Experience decay is an automatic mechanism and is independent of which and how many skills are used – not using or frequently using a skill (or other, unrelated skills) has no effect on the rate of decay, which only depends on the current skill level. Instead, gained XP simply cancels out loss and vice versa on a 1-to-1 basis.
XP is lost at a faster and faster rate with higher skill levels. This means that all XP earned after 55,000 total XP effectively has less value, especially for skills that a colonist does not use frequently, because it will disappear. It becomes more and more expensive to even keep a master at his or her current level, let alone have them improve further.
As an example, consider that roughly 3,500 XP is lost per day by a colonist at skill level 20. This usually means that the colonist would have to be applying that skill more or less continuously during her work hours in order to never lose level 20. In most cases, XP is gained by time spent on a skill, and not by effective work performed! Working faster does not make it easier or faster to gain XP, or compensate the decay loss.
So the higher you go, the harder it becomes to even maintain the current skill level. This is why actual "legendary masters" are very rare, usually only achievable by colonists who are non-stop spamming a single ability (such as research or crafting artworks).
Traits and other factors
Several traits affect pawn skills. Some directly add or subtract from the skills of the pawn - such as Brawler which increases the Melee skill by +4 and decreases Shooting skill by -4. Others affect skill mechanics themselves. These include:
- Great Memory - which halves the skill decay rate for a pawn.
- Too Smart - which increases Global Learning Factor +75%, while also inflicting a penalty to mental break threshold.
- Fast Learner - which increases Global Learning Factor +75%
- Slow Learner - which decreases Global Learning Factor -75%
Additionally, the learning assistant 
implant increases Global Learning Factor +20%.
Experience table
Level 20 is the highest skill level achievable for a pawn.
| Level | Name | Total experience required | Experience till next level | Experience decay rate (exp/day) |
|---|---|---|---|---|
| - | Incapable | - | - | - |
| 0 | Barely heard of it | 0 | 1000 | 0 |
| 1 | Utter Beginner | 1000 | 2000 | 0 |
| 2 | Beginner | 3000 | 3000 | 0 |
| 3 | Basic Familiarity | 6000 | 4000 | 0 |
| 4 | Some Familiarity | 10000 | 5000 | 0 |
| 5 | Significant Familiarity | 15000 | 6000 | 0 |
| 6 | Capable Amateur | 21000 | 7000 | 0 |
| 7 | Weak Professional | 28000 | 8000 | 0 |
| 8 | Employable Professional | 36000 | 9000 | 0 |
| 9 | Solid Professional | 45000 | 10000 | 0 |
| 10 | Skilled Professional | 55000 | 12000 | 30 |
| 11 | Very skilled Professional | 67000 | 14000 | 60 |
| 12 | Expert | 81000 | 16000 | 120 |
| 13 | Strong Expert | 97000 | 18000 | 180 |
| 14 | Master | 115000 | 20000 | 300 |
| 15 | Strong Master | 135000 | 22000 | 540 |
| 16 | Region-Known Master | 157000 | 24000 | 840 |
| 17 | Region-Leading Master | 181000 | 26000 | 1200 |
| 18 | Planet-Known Master | 207000 | 28000 | 1800 |
| 19 | Planet-Leading Master | 235000 | 30000 | 2400 |
| 20 | Legendary Master | 265000 | 32000 | 3600 |
List of skills
Using or applying skills will give experience in the skill, and improve the character's proficiency. How much experience is gained depends on the passion for the skill. See passion below.
On this page, where experience gains are listed, an "Interested" passion with 100% skill gain is assumed. Note that this is not the "default" passion; "no passion" at 35% gain is far more common.
Animals
The animals skill determines how well a character handles wild and domesticated animals, and increases the chance to go undetected while hunting wild animals.
Higher animals skill has the following benefits:
- Chance to tame a wild animal increases. Some animals can not even be attempted to be tamed if the animals skill is too low.
- Chance to successfully train a domesticated animal increases.
- Animal handling, such as milking and shearing certain livestock, becomes more efficient, with a lower chance of wasting products.
- Mastering an animal, as in having it follow you and obey your commands, becomes possible for more animal races. The more wild a race is, the higher the animals skill required to be assigned its master.
- It becomes less likely for a colonist hunting an animal to be detected by the animal, and the animal retaliating. It still requires shooting skill for the colonist to be able to kill the animal.
| Description | Base Factor | Bonus Factor | |
|---|---|---|---|
| Animal Gather Speed | The speed at which this person milks, shears, and otherwise gathers resources from animals. | 0.04 | 0.12 |
| Animal Gather Yield | The percentage yield someone receives when they shear, milk, or otherwise gather resources from a living animal. Higher percentages reduce the chance of wasting the product. | ||
| Hunting Stealth | This stat reduces the chance of hunted animals attacking the hunter. A 0% score means no reduction. A 100% score means animals never attack. | 0 | 0.05 |
| Tame Animal Chance | The base chance this person will successfully tame an animal on any given attempt. The actual chance is also affected by the animal's wildness. Failed tame attempt can induce animal attacks, especially for more vicious animals. | 0.04 | 0.03 |
| Train Animal Chance | The base chance this person will make progress training an animal on a given attempt. The actual chance for a given attempt will also depend on the animal's wildness, whether it is bonded with the trainer, and so on. | 0.1 | 0.05 |
Artistic
The artistic skill is the proficiency to create beautiful works of art at a sculptor's table.
Higher skill increases the chance for a higher quality, in this case more beautiful, sculpture. Note that higher skill levels do not increase the speed of creating sculptures.
The beauty and market value of sculptures increases tremendously at the highest quality levels. Combined with the fact that trade partners pay more for works of art compared to other items, this makes artistic a useful skill outside of decorating the home base.
Not very useful in the early game, but once you have a well-established colony, having a permanent artist would be beneficial to it.
Construction
The construction skill governs a wide variety of colonist tasks, centered around creating structures in the game world; it is an essential skill in any colony:
- Making all kinds of structures, like furniture, walls, power lines and spaceship parts. If a structure can be placed on the ground in form of a blueprint, its construction is usually facilitated by this skill. Many structures require a minimum skill to make.
- Deconstructing existing structures back into raw materials.
- Building and tearing down roofs.
- Laying and removing flooring, like carpet, concrete and stone tiles.
- Smoothing rock walls and stone floors.
Higher construction skill will
- allow the construction of more difficult to build structures.
- increase construction speed; the base speed at 0 construction skill is 50%, this is increased additively by 15% for every skill level.
- reduce the chance of a construction effort to be "botched", which will result in some resources going to waste, and require the construction effort to be restarted (ie. all work is wasted). The base chance of success is 75%, increasing by about 3% per skill level to 100% at skill level 8.
- increase the chance to make higher quality items, for items that have a quality rating, such as furniture.
Construction outcomes are influenced by the manipulation and sight capacities of the colonist.
Experience is gained continuously while working on a construction project. At 100% work speed this seems to translate to roughly 82 experience per point of work required.
| Description | Base Factor | Bonus Factor | |
|---|---|---|---|
| Construct Success Chance | The chance that this person will succeed in constructing something. Failing means wasting time and resources. | ||
| Construction Speed | Speed at which this person constructs and repairs buildings. | 0.3 | 0.0875 |
| Repair Success Chance | The chance that this person will successfully repair a broken down building using a component. Failing means wasting time and resources. Note that this only applies to repairing breakdowns, which is different from repairing damage. | ||
| Smoothing Speed | A multiplier on the speed at which this person smooths rough stone floors and walls. | 0.3 | 0.0875 |
Items with a required Construction skill level:
Cooking
The cooking skill affects how long it takes to cook meals and butcher dead creatures, as well as the Food Poison Chance for the person who eats the meal. It also affects Butchery Speed and Butchery Efficiency, how much meat is produced when butchering.
Cooking and butchering increase cooking skill. It is also trained by making smokeleaf joints at a drug lab.
A cooking skill of at least 6 is required to make a fine meal.
A cooking skill of at least 10 is required to make a lavish meal.
These additive increases are relative to a base value; that means each increase corresponds to a fixed amount.
| Project | Experience Given Per Task |
|---|---|
| Simple Meal | 60 |
| Fine Meal | 110 |
| Lavish meal | 160 |
| Pemmican | 80 |
| Description | Base Factor | Bonus Factor | |
|---|---|---|---|
| Butchery Efficiency | The amount of meat produced when butchering flesh creatures. The actual amount is also related to the creature's size. | 0.75 | 0.025 |
| Butchery Speed | Speed at which this person butchers flesh creatures. | 0.4 | 0.06 |
| Cooking Speed | The speed at which this person cooks meals. | ||
| Drug Cooking Speed | The speed at which this person brews beer and tea, or makes simple drug products like smokeleaf joints. | 0.4 | 0.06 |
| Food Poison Chance | The probability that this character will inadvertently poison a meal they cook. Anyone who eats a food-poisoned meal will be temporarily debilitated with pain, weakness, and vomiting |
Crafting
The crafting skill affects the smith, tailor and craft work types.
The Crafter's skill is a driving factor in the quality of crafted clothing and neolithic weapons.
The crafting skill determines the time it takes for a colonist to extract metal from slag and disassemble mechanoids. It also determines the amount of resources produced.
| Description | Base Factor | Bonus Factor | |
|---|---|---|---|
| Mech Gestation Speed | A multiplier on the speed at which this mechanitor can form new mechanoids at a gestator. | 0.75 | 0.025 |
| Mech Repair Speed | A multiplier on how fast a mechanitor can repair mechanoids. | 0.8 | 0.1 |
| Mechanoid Shredding Efficiency | The amount of materials yielded when this person shreds a dead mechanoid for resources. The actual amount is also related to the mechanoid's size. | 0.75 | 0.025 |
| Mechanoid Shredding Speed | The speed at which this person can shred a mechanoid for resources. | 0.4 | 0.06 |
| Subcore Encoding Speed | A multiplier on how fast a mechanitor can create subcores. | 0.75 | 0.1 |
Items with a required Crafting skill level:
Medical
The Medical skill level is the main factor for medical treatment quality and speed, surgery speed and surgery success chance.
Low quality treatment will increase the chance of infection, and the likelihood of permanent health conditions such as scars, in turn leading to chronic pain. Certain scars cause more than 10% pain, permanently weakening the consciousness of the patient, which reduces their work performance.
Medical surgery, if not successful, can fail in minor or major ways, even causing the death of the patient. The success rate is not only determined by the medical skill, but also other character stats like manipulation, eye sight and consciousness. It is not advisable to let an incapacitated doctor perform surgery.
Higher grade medicine and medical equipment like hospital beds and a sterile environment significantly boost the effectiveness of all medical treatments, independent of the skill level of the doctor.
Medicine can be trained very quickly by performing euthanasia on fast-breeding animals such as chickens. This costs 1 medicine per procedure, but only requires herbal medicine. The procedure can be scheduled in the respective animal's health tab, and an animal sleeping spot must be available to perform the euthanasia.
Performing surgery trains the medical skill. The amount of XP that is awarded only depends on the duration of the procedure (varying by procedure and medical operation speed of the surgeon).
| Description | Base Factor | Bonus Factor | |
|---|---|---|---|
| Medical Operation Speed | The speed at which the character performs medical operations. | 0.4 | 0.06 |
| Medical Surgery Success Chance | The likelihood that a colonist will succeed when attempting to perform a surgery. The actual success chance is also affected by factors like facilities, room cleanliness, medicine used, the difficulty of the surgery, and inspirations. No matter how high this stat is, there is always a small chance of failure on any operation. | ||
| Medical Tend Quality | The base quality of tending given when tending wounds and illnesses.
Final Tend Quality: ( ( ( ( (Medical Tend Quality Stat from Doctor) * (Medical Potency) ) + ( Medical Tend Quality Offset from Bed ) ) * ( 0.7 if Self-Tend) ). Multiplied by a random + or - 25% and clamped to between 0% and the Maximum Tend Quality from the medicine used. Standard bed is not a factor. Only hospital beds have a Medical Tend Quality offset. Light is not a factor of Medical Tend Quality. Light is likely a factor of Medical Tend Speed and Surgery Success chance. Cleanliness is not a factor of Medical Tend Quality. Cleanliness is a factor of Infection Chance. Indoors is not a factor of Medical Tend Quality. Indoors is a factor of cleanliness and thus Infection Chance.
| 0.2 | 0.1 |
| Medical Tend Speed | Speed at which the character tends to wounds and illnesses. | 0.4 | 0.06 |
Melee
The melee skill determines a characters' chance to:
- Land a hit in melee (see Melee Hit Chance)
- Dodge a melee attack, when not aiming or firing a ranged weapon (see Melee Dodge Chance)
The tables below are post-processed chances for a healthy pawn.
|
Chance to hit
|
Chance to dodge
|
| Description | Base Factor | Bonus Factor | |
|---|---|---|---|
| Melee Dodge Chance | Chance to dodge a melee attack that would've otherwise hit. Characters will not dodge while aiming or firing a ranged weapon. | ||
| Melee Hit Chance | Chance to hit a target in melee. The target can still dodge even if we would've hit. |
Mining
The mining skill determines how long it takes for a colonist to mine out each rock, and how much they can obtain from each mineral vein mined.
| Description | Base Factor | Bonus Factor | |
|---|---|---|---|
| Deep Drilling Speed | A speed at which this person uses a deep drill to extract underground resources. | 0.04 | 0.12 |
| Mining Speed | A speed at which this person mines away walls. | 0.04 | 0.12 |
| Mining Yield | The percentage of mined resources a miner will produce. This applies to both wall mining and deep drill mining. This doesn't affect the production rate of rock chunks from deep drills. |
Intellectual
This skill affects the speed at which research is completed.
| Description | Base Factor | Bonus Factor | |
|---|---|---|---|
| Activity Suppression Speed | The speed at which this person can suppress unnatural entities. A higher speed means they take less time to suppress each entity. | ||
| Drug Synthesis Speed | How fast this character synthesizes complex chemical drugs. | 0.3 | 0.0875 |
| Entity Study Rate | The rate at which this person generates knowledge from studying unnatural entities. | 0.08 | 0.115 |
| Hacking Speed | How fast this person can hack into computer terminals. | 0.75 | 0.025 |
| Reading Speed | A multiplier on how fast this person can read. | 1 | 0.02 |
| Research Speed | How fast this person performs research and how quickly they can find things using scanning equipment. | 0.08 | 0.115 |
Plants
The plants skill affects how fast a colonist sows and harvests growing zones, hydroponics and flower pots, and how fast trees and other vegetation is cut down. It also influences how much a colonist forages while in a caravan. See Plant Work Speed Each point increases speed by 11.5%.
| Project | Experience Given Per Task |
|---|---|
| Harvesting | 50 |
Some plants require a minimum plants skill in order to plant them:
| Description | Base Factor | Bonus Factor | |
|---|---|---|---|
| Foraged Food Amount | The amount of nutrition this person will automatically forage per day while traveling by caravan. | 0 | 0.09 |
| Plant Harvest Yield | The yield this person gets when harvesting plants. Low yields give a chance that this person will accidentally waste the harvest. | 0.6 | |
| Plant Work Speed | Speed at which this person sows and harvests plants. | 0.08 | 0.115 |
| Pruning Speed | A multiplier on how fast this person can prune a Gauranlen tree to maintain their connection with it. Pruning is more of a contemplative psychic task than a physical one, so health factors like vision are unimportant here. | 0.92 | 0.01 |
Shooting
The shooting skill affects a character's accuracy with ranged weapons.
The table below shows post-processed shooting accuracy per tile of distance for each skill level and trait combination, assuming the pawn is healthy:
| Skill Level | Standard | Careful Shooter | Trigger-Happy | Skill Level | Standard | Careful Shooter | Trigger-Happy |
|---|---|---|---|---|---|---|---|
| 0 | 89% | 94.5% | 84% | - | - | - | - |
| 1 | 91% | 95% | 85% | 11 | 97.25% | 98.333% | 95% |
| 2 | 93% | 95.5% | 86% | 12 | 97.5% | 98.5% | 95.5% |
| 3 | 93.5% | 96% | 87% | 13 | 97.75% | 98.666% | 96% |
| 4 | 94% | 96.5% | 88% | 14 | 98% | 98.833% | 96.5% |
| 5 | 94.5% | 97% | 89% | 15 | 98.167% | 99% | 97% |
| 6 | 95% | 97.25% | 91% | 16 | 98.333% | 99.125% | 97.25% |
| 7 | 95.5% | 97.5% | 93% | 17 | 98.5% | 99.25% | 97.5% |
| 8 | 96% | 97.75% | 93.5% | 18 | 98.666% | 99.313% | 97.75% |
| 9 | 96.5% | 98% | 94% | 19 | 98.833% | 99.375% | 98% |
| 10 | 97% | 98.167% | 94.5% | 20 | 99% | 99.438% | 98.167% |
Note that shooting accuracy for the pawn is calculated per tile, meaning that while a trivial increase (like 1% or so) in shooting accuracy may not matter up close, it can make a huge difference in long distances.
For example:
- A colonist with shooting accuracy of 99% has a base accuracy of 72.5% against a target 32 tiles away.
- With 98% accuracy, the base accuracy against the same target becomes only 52.4%.
The base accuracy at various distances are listed when you check the information of a pawn. This can show the actual shooting performance of a pawn, especially at long ranges.
| Description | Base Factor | Bonus Factor | |
|---|---|---|---|
| Hunting Stealth | This stat reduces the chance of hunted animals attacking the hunter. A 0% score means no reduction. A 100% score means animals never attack. | 0 | 0.05 |
| Mortar Miss Radius Multiplier | A multiplier on the miss radius of a mortar used by this person. Smaller numbers means more accurate mortar shells. | 0.2 | -0.025 |
| Shooting Accuracy | Base chance to not miss per cell of shot distance. Chance to hit is also affected by many other factors. A hit chance explanation for any shot can be seen by selecting a shooter and mousing over a target. |
Social
The social skill affects the impact of social interactions on other characters' mood, the impact of gifts on faction relations, the recruitment chance for prisoners and trader prices. A small amount of experience is gained every time two colonists have a social interaction with each other. Characters have a talking stat that somehow interacts with this skill
| Description | Base Factor | Bonus Factor | |
|---|---|---|---|
| Activity Suppression Speed | The speed at which this person can suppress unnatural entities. A higher speed means they take less time to suppress each entity. | ||
| Arrest Success Chance | How effective this person is in arresting people. This affects chance that this person will be able to arrest someone without resistance. | 0.6 | 0.075 |
| Conversion Power | How effective this person is at converting others to their own ideoligion. When this person attempts to convert someone else, this value multiplies the amount of certainty the other person loses. | 0.3 | 0.0875 |
| Negotiation Ability | How effective this person is as a negotiator. This affects the speed of prisoner recruitment, impact on faction relations when giving gifts, and the outcome of peace talks. | 0.4 | 0.075 |
| Social Impact | A multiplier on how much other people are affected by this person's social interactions. | 0.82 | 0.0275 |
| Suppression Power | A multiplier on a warden's ability to suppress slaves. | 0.05 | 0.0225 |
| Trade Price Improvement | When this person acts as a trade negotiator, buy and sell prices are improved by this percentage. | 0 | 0.015 |
Passion
The learning speed in a skill depends on the passion for the skill. Passions are indicated by a flame icon next to the skill experience bar on the character's Bio tab.
Most commonly there is no passion for a skill, and the character learns this skill at 35% of the base rate.
There is absolutely no way to change a character's skill passions in the unmodified game.
There are colonist traits that give global bonuses to skill learning: "Too smart" and "Fast Learner" both increase all skill acquirement by 75%. This is independent of the passions for the individual skills. Effects from these traits are not correctly explained in a skill's tooltip information.
Once colonists have acquired 4000 XP in a skill, per day, further learning of this skill is sharply reduced to 20% of the usual rate. This is indicated when mousing over a skill bar in the Bio tab.
Skill gains from using a neurotrainer mech serum are influenced by passion. This makes the item a lot more valuable when used by characters with a passion for the associated skill.
Effect on mood
Passion influences a character's mood. If the pawn is "interested in" or "burning for" learning a skill, this gives them a substantial mood boost for the duration of the activity.
- Interested gives +8 mood ("Minor passion for my work").
- Burning gives +14 mood ("Burning passion for my work").
In some cases this effect is not visible, if the activity is intermittent (such as hunting animals).
The significant mood boosts can be used to keep a pawn from heaving a mental break by putting them on a task they are passionate for.
Degrees of passion
The three levels of passion are:
None
Skills with no flames; can be considered the default passion for a skill, and is the most common. Characters with no passion for a skill only gain experience at 35% of the standard rate.
Interested
Skills with one flame. Characters that are interested in a skill will gain experience at the standard rate of 100%.
Burning
Skills with two flames. Characters with a burning passion for a skill will gain experience at 150% of the standard rate.
Version history
- 0.0.245 - Skills now cap at 20. Added cooking, medicine, artistic, crafting but currently do nothing. Rebalanced shooting and melee to make skill more important. Shooting accuracy split into into misses due to equipment and misses due to skill.
- 0.2.363 - High level skills now decay. Passions system added.
- 0.9.722 - Old pawns now tend to spawn with higher skills. Low skill cooks can now cause food poisoning.
- 0.10.785 - Passion flames are now displayed subtly on the work overview screen. Reduced skill degradation rate. Reworked how skills generate so there will be more initial skill variation and age affect starting skills more.
- 0.12.906 - Animals skill added.
- 1.2.2753 - Pawns will now not lose their skill levels until they fall 1000 XP under zero. This stops pawns from quickly leveling up and down around a threshold. We now display a text mote when a player pawn gains a new level in a skill.