In the most extreme cases, slaves would probably start getting accused of crimes they did not even commit and had their supply of food taken away from them so that they would suffer from hunger and malnutrition for their insolence. There might also be cases where a whole group of slaves might be unilaterally punished for the sins of just one of them, simply to prevent them from even thinking of ever doing what the offender had done if they know what is good for them.
However, I wonder how are the things in this world from a purely medical standpoint. My previous world, the twenty first century one is the kind of world that is so technologically advanced that there are very little cases of diseases that cannot be cured at all, and the people who are afflicted with them are not doomed live a miserable existence, but can instead still enjoy a relatively long life, even in the face of something as serious as cancer. But as for this world I am living in right now. . . . . . . well, let me just put it this way: if your head is being filled with suicidal or nihilistic thoughts when your MP gets completely depleted, then something is telling me that this world might have a serious problem when it is going to be hit with diseases such as dementia or depression.
As for the housing situation. . . . . . . . . . . . . in Japan, up until recently there was this trend where it was not uncommon for the three whole generations of the families: grandparents, parents and children to live in the same house, but from what I have heard that trend seems to be on the decline now because an increasing percentage of young people wants to live and work in the big cities were they can be independent from their parents. . . . . . . . . but can such a situation really be likened to having a master living in one home with a bunch of his slaves? No, definitely not. These two situations might appear to be similar when we look at them purely from the perspective of numbers and logistics, but are completely different when you start delving deeper into them. In modern-day Japan, and probably across the rest of the world as well, even if large families live together under one roof, usually there is no need for everyone to constantly keep tabs on one another and have all of the members of the household under constant surveillance. In most cases, usually the members of the three generations living in the house tend to not interfere with one another and simply live out their lives as they normally would, but there is still that particular feeling of familial bond between all of them, which prevents the situation from devolving into the one where it is basically that one house is inhabited by six or more complete strangers. But since in this world it is customary that a long-term care of the children is often relegated to slaves (and probably servants and maids in case of wealthier members of the nobility as well) so I think that if it ever came to the situation that a family that has slaves would be forced to live with the members of their extended family, or in come cases maybe even their in-laws, then I highly doubt that they would try to make an effort to talk and keep in touch with them. The most likely scenario in such case would probably be that the head of the household would simply order the slaves to take care of the needs of the extended family members, and that would probably be it. No complaints, no protests, just acceptance from both sides that this is simply how the things are supposed to be. And that, to be honest. . . . . . . . is kind of sad, actually.
All right, let us say that I can more or less wrap my head around how that second way works. There are points that could definitely use some ironing out in my opinion, but we will worry about that some other time. Anyway, that leaves only one way of treating slaves to discuss, right?
Yes, and the third way of treating slaves is buying them exclusively so that they would explore the Labyrinths for their master, and nothing else beside that.
That sounds really similar to the second one that you mentioned.
On the other hand, the slaves who enter the Labyrinths have one advantage over their master: they can actively increase the Level of their Job and become progressively stronger, so with enough time spent on dungeon crawling and Levelling Up, it might not be impossible for them to one day become strong enough to proclaim themselves stronger than their master, but that is only under the assumption that the master is someone who only sends their slaves to gather the items in the Labyrinths while they themselves simply stay in the safety and warmth of their house, because the story is going to be different if the master chooses to go to the Labyrinth together with his slaves. And since the EXP points are always divided equally between all the Party members, the slaves would not be able to earn more EXP than their master, who would simultaneously be the Party Leader as well.
But just as Sherry and Roxanne said: as the levels go up and the slaves going to the Labyrinths become stronger, their treatment is going to drastically improve. The stronger they become, the harder it will be for them to die while fighting the monsters in the Labyrinths, and they are going to secure their position further, since it would be inefficient and unwise to get rid of your strongest Party Members just so that you could replace them with weaker ones.
After all, if you do not have access to Bonus Skills that increase the amount of the EXP that you obtained from defeated monsters, the process of gaining levels is going to take a long time, and it is extremely unlikely that the slaves going to the Labyrinths would be able to increase their levels to something around Lv.40 or Lv.50, even if they were going there every day and stayed inside for the majority of the day, so it is not like they would be swaggering around trying to look all important if they did not have the stats and strength to back that up.
Master, I want you to know that I am only telling you what I am about to tell you because I know how good of a person you are, okay? So, it seems that there is also a possibility of striking an agreement with the strong Labyrinth-going slaves that would allow you to buy them from their masters if they conclude that they are being treated especially badly, and sometimes even the slaves themselves can come up with such a initiative.
So such a thing can happen, huh? Well then, I guess I will have to make sure that I treat Roxanne and Sherry especially well to make sure that does not. . . . . . . . happen. . . . .
Right then, a certain thought has downed upon me.