A skill is a special magecraft enhancement made through the World System that transforms part of the soul to easily draw out the power that all living things own. 

The more skills one has, the more of the soul's natural power is released. The soul naturally has a limit to how much power it can produce, which will mean the number of skills one can obtain is limited as well.

The World System, however, can forcefully mature the soul beyond those limits, which will lead to a higher possible number of skills.

In some cases, the skill holder can obtain too many skills, which will inflict them with the "Waning" status ailment. Waning reduces the skill holder's total stats, and will not be lifted until one's soul has been developed enough to withstand the high amount of skills. In the worst case, Waning can lead to the death of the skill holder.

Waning can be lifted by either:

• Stop acquiring new skills for a while, giving the soul some time to rest and stabilize,
• Reducing the total number of skills, such as merge-evolve a pair of them. Some skills, such as certain Resistance Skills, does this automatically.
• Toughing it out with guts until one's developed the soul even further. Increasing one's racial level is a good idea for this.

While gaining too many skills can lead to Waning, developing the skills one already has will not.

Constant training of skills one already has will improve the rate of skill proficiency, which will make it even easier for skills to gain new skill levels, producing a snowball effect that constantly improves one's skill proficiency gain.

In other words, constantly using skills will train one's soul so they can learn new skills and improve those they already have at an alarming rate.

Passive Skills or skills that are used for everyday life objects are the best for the above-mentioned strategy.

Every creature is born with the capability to obtain a total of 5 skills without having to pay any costs. These are referred to as Inborn Skills.

In some cases, there can be one or more skills that all races are born with as their Inborn Skills. These obligatory skills are counted as the 5 Inborn Skills. For the other Inborn Skills that are not limited to the skill holder's race, they will be automatically decided based on the talents and/or living style those people have in their childhood.

Skill Points are the numeric value of the soul's stored energy, which the World System can use to transform part of the soul with a skill.

Skill Points can be acquired either by increasing one's racial level, through special means such as special potions or given as Quest Rewards for Quests given by the World System (and by extension, the Adventurers' Union), or simply by developing one's soul throughout the years.

When one kills a living thing, that creature's soul's energy will be released as a type of energy referred to as Experience Points, or EXP. The killer of the creature will absorb a certain amount of this energy, which will lead to their own soul's growth, and once the soul reaches a certain stage, it will increase its racial level. One can also obtain EXP through special Quests, or simply by living for long enough.

Skills transform only the surface area of the soul. This allows the skill holders to access their new powers with relative ease. Some skills, however, can be straight out defective for the skill holder. 

Ability Skills are skills that enhance the soul's performance with their physical body, more precisely, their status values such as Strength and Vitality. While these skills allow the skill holders to gain status values above their race's natural limits, they do not directly empower the body. On the flip-side, they allow the body of the skill holder to grow to a higher than normal degree for that race. It is the skill holder's responsibility to make sure that they train their bodies to be able to use those stats, not the skills'.

Some skills cannot be used to transform the soul, due to said skill not being compatible with the potential skill holder. These skills are named Racial Skills. While there are some exceptions, Racial Skills are strictly limited to certain races that own special Traits, but sometimes, these restrictions can be bypassed through certain means. 

Some skills may require more Skill Points than others. This could either be because the person in question has worse compatibility with said skill, or the skill being naturally more advanced than others.

Some skills, when reaching their highest skill level, unlock derivations of themselves for the skill holder to unlock in the Skill Shop, or it will unlock skill-evolutions which drastically improves the abilities of the skill. These require at least 5 more Skill Points than the original skill's value.

There are some skills one should stay away from. The [Undead Element] skill is one of them. It gives the skill holder the attribute of the undead, meaning that if someone still alive acquires this skill, the Undead attribute will cause a malfunction of the life-force energy of the skill holder, which will result in their death.

This makes the Undead Technique User title limited to those already undead, or those with a Spectermancer-line class as their main class, due to its hidden effect of preventing this malfunction, but only when these classes are selected as the main class.

Other skills one should be wary of are the Extra Skills. These are super-powerful skills that can only be obtained after clearing super-difficult trials in the form of some Legacy Quest given by the gods themselves, or by training as crazy in some skill that will turn into an Extra Skill as its final stage. Like, "dedicating your whole life to training"-level of craziness.

The real danger regarding Extra Skills is not the difficult requirements one must fulfill to attain them, but rather what happens next.

As said before, normal skills only transform the surface area of the soul, and nothing else. Extra Skills, on the other hand, transforms the inner regions of the soul, sometimes resulting in serious side effects.

While some Extra Skills are safe to obtain and use, some even have a few perks as unlocking previously unattainable skills, many of these skills can drastically change a person's soul. The worst candidates include the Outer Gods skills. These are so horrible to use without falling into madness that they are seen as some sort of sick joke by the Ultimate Gods.

Among the "usable" Extra Skills, a certain group of skills is notably different and questionable. These are the Seven Sins Skills and Seven Virtue Skills.

These skills are strange even for Extra Skills. First, they are unique skills in that there can only be one owner of these skills at once in the world, and two, they can all be obtained from the Skill Shop after completing some requirements.

For Sin Skills, one needs to evolve a certain skill twice, with the second evolution being the Sin Skill. The evolution for the Sin Skill requires more Skill Points than for a normal skill. The price may be lessened if the possible skill holder has great compatibility to that sin, personality-wise.

The Virtue Skills on the other hand requires the potential skill holder to attain a certain title for that Virtue, then advance said title to its next stage. After that, it becomes possible for the Virtue Skill to be bought from the Skill Shop. Again, the number of Skill Points required for these skills is mind-numbing, however, having great comparability with said Virtue, such as with the Sin Skills, can help with that.

The real problem with these skills is that extended use of these skills may result in the skill holder being taken over by the Sin/Virtue. The result will be a "something" incapable of other emotions or desires than those of the Sin/Virtue in question. 

There are three countermeasures to this. First: do not obtain an Extra Skill in the first place. Two: do not use it too often for the soul to be contaminated by it. Three: put some effort into the [Heretic Resistance] and [Heretic Immunity] skills and merge them into [Heretic Nullification]. The side-effect of the Extra Skills is considered an attack in the eyes of the Resistance Skills, so having them at a high level, if not the highest, should counteract the contamination. Trying to increase the skill levels with the Extra Skill itself is not recommended.