Jack had been laying on his lair, his back against a huge chair made of sandalwood. Where did it come from? From the extorting mana taxes he imposed on his subjects, of course!
As for his couple-meters-wide piece of pomice? He was using the tip of his claws to slowly grind it on the ground.
Elicia, by his side, observed the action with a bit of a phew. She looked weary, as one would be after expending days and more days grinding small pebbles on the ground.
Why?
Because that was one of the means through which she could increase many of her skill trees, by stimulating concentration, focus, stamina, resilience…
A tedious, boring and spirit-grinding task like grinding rocks in the ground for days without end while also paying close attention to what she was doing - this would increase mastery of the so-called elementary skills associated with many, many skill trees.
Basically, elementary skills such as concentration were determinant in things like the ability of a mage to progress in stage and learn the mages' passive skill "Mental Fortitude" or the Psion skill "Unwavering Mind".
Players would usually grind these skills while out in the wild, facing monsters, becoming able to live with dangerous situations and multitask their own mental skills.
Many corporations in the real world used to send their employees on "mind training" sessions inside Another World. There they would develop multitasking and stress-managing real skills, and before receiving the games' skills like "Mental Fortitude" their minds would have been trained already.
As for Jack and Elicia… they were both dragons to begin with, so it wasn't easy to find opponents to face against. Even if Jack used his Dugeon to summon strong monster for Elicia to fight, he wouldn't dare to summon a monster which was strong enough for him to have to train hard.
And as for Elicia, she wouldn't lose precious time and focus with that as well.
What was a "skill"?
Another World was a place were peoples' minds were placed inside artificial "flesh" bodies, which had their own brains, nervous system and so on.
The impulses Jack and Elicia felt, as well as the adrenalin rushes and fear, or lose of concentration one would face while in battle, were all related to the brain. If ones' brain was wired in such a way that they would be greatly overwhelmed with emotion in a life-and-death situation, then they would lose concentration. If their brains were wired in such a way that their desire and pleasure with gold was so great that they would go against their loved ones for it, then they would do it.
Skills were little "magical helps" the world system would give to people. Once a certain task had been done a certain number of times, depending on the persons' race and so on, their artificial brains would have been re-wired on a certain manner. Once that happened, the systems' "fairy dust" would manifest and help to make that wiring the most effective as possible.
One could say a skill was the world "rewriting" ones' brain in accordance to ones' ability to rewire it in the first place.
So, stupid and repetitive tasks like grinding rocks on the ground while paying attention to that actually meant that, once that was repeated enough times, the magic in the air would rewire Elicia and Jacks' brain in the best possible way once they progressed on the skill trees - that is, once they used their concentration powers to recite or mentally launch magic, or to brand swords, and so on.
Days of grinding would be perfectly optimized to mean days of sword-swinging, magic-reciting, meditation and so on - with certain limits, of course.
The most basic skills wouldn't amount to much, as while the most advanced ones would near perfect brain wiring.
Still, that wiring would only mean a certain number of days of concentration, focus or so on, and the number of days was determined by the value of the elementary skills.
If someone had an elementary skill of concentration at level 5, which meant 5.000 hours of regular concentration (concentration under stress and hyperfocus accounts for extra hours each minute), that would mean getting the "Mental Fortitude" skill would translate into a brain wired as if the person had gone through 5000 hours of reciting and concentrating to cast elementary magic spells.
Of course, since this was a level 20 skill, that would be a half-assed wiring.
Then, if that person got the "Warriors' Heart" skill, that would mean receiving, as well, 5.000 hours of concentration on sword training.
As for level 35 skills such as "Fire Storm Caster" and "Vertical Swing Battler", one would get 5000 hours of in-battle wiring, as if one had been 5000 hours battling with the Fire Storm spell and vertical swings. Also, a slightly more efficient all-round concentration wiring would be gained.
So, in the end, for Jack and Elicia who both needed to master a great number of low-level concentration and self-restraint skills in order to be able to restrain their urges as soon as possible, raising the elementary skills in a fast and efficient way was a must - as doing so would increase the efficiency of all those skills.
Grinding stones on the floor it was, then.