A "permanent loss" is the price one pays to come to Paradisa. To date, no one has ever found a way to retrieve all that is lost –– even those who live in the Dead Zone (the "Free People") have acknowledged that there is no known way to take back what has been stolen, at least not without sacrificing something else in its stead. And, as most residents have discovered already, when you are playing against the castle, you are playing with a deck stacked in the castle's favour.
As for what losses can be, they can be anything imaginable, but it is always something precious and dear to the resident. Often, losses tend to be an ability, a skill, an item or a memory. Sometimes it may be a combination, or some strange, more abstract thing.
Ability or skill losses strip a resident from being able to do something that is important or vital to them. Perhaps they will lose the ability to dress themselves alone, or the ability to feel a certain emotion, or all knowledge of a particular subject. These skills and abilities cannot be relearned or re-taught. The loss acts as a physical restraint or a mental block, impossible to fight back against.
Item losses are when the castle takes an item that is extremely important to the resident. This item is always something that the resident keeps with them at all times, such as a weapon, or a special keepsake, or something else of significance. This item can not be retrieved, nor will the castle give out replicas or similar items.
Memory losses are common as well, and they act as mental blocks. The memory may be of a precious person, an event, a time period, or any other important memory. Sometimes it strips their memory so finely that the resident does not recall the memory as having ever existed, and sometimes it only removes certain things about the memory. Sometimes, when losing the memory of an event, the castle substitutes in an altered memory of it, or other times it just leaves them with a large blank. Residents often learn all about the people or events they forget from other residents, but it will never be the same as having remembered it personally.
However, regardless of the type of loss, Paradisa will never hand out a loss that can be circumvented. It goes all out or it doesn't at all, essentially; it will never take only some of a resident's strength, or leave them with any fail-safes. When a resident is in a desperate situation, Paradisa will never give any slack, or grant them any leniency. When it takes, it takes. Residents must adapt without the lost pieces of themselves.
It is also known that losses can change when the resident is killed or knocked unconscious, but it is also known that being killed can give a resident an additional loss, rather than changing it. This additional loss may sometimes involve another resident or memories from Paradisa as well, though the initial loss is always something from their home universe.
Residents of the castle know that they have one (possibly more) permanent “loss” of something. However, it’s also become common jargon within the community to refer to temporary events as “losses” as well, though these temporary losses don’t necessarily involve losing anything. A “temporary loss” is, essentially, the castle messing with something.
These events usually come in the form of a strange affliction that lasts anywhere from a few days to a month, though the most common amount of time is a week. This affliction can be almost anything, from being forced to tell the truth all the time to being incapable of speech, to being turned into an animal or being turned into an alternate version of themselves. Residents have become rather forgiving of these events, as radical changes tend to cause trouble between people, but they remain frustrating, painful, or sometimes just plain entertaining ordeals for those involved. Sometimes residents are afflicted in pairs or in larger groups, as well.
No one has a precise answer as to what triggers them, either. Some residents experience them on a regular basis, while others can go years without experiencing one. In times past, sometimes the castle would dole out temporary losses them after residents made particularly large demands from the castle, such as asking for complex items or animal life, but these penances don't seem to happen anymore. Instead, it seems entirely up to the whims of the castle.
All losses, however, entail that the resident retain some part of their identity during it, to ensure that they are still residents of the castle. A resident will never be turned completely into someone else –– if Paradisa wanted that person in the castle, it would just bring them there personally.
Discouraged Temporary Losses
Generally speaking, the possibilities are pretty much infinite. There are classics, such as being turned into a child or being put into the body of the opposite sex, or the “Ella Enchanted” loss, where residents must obey any command given to them. The castle also enjoys making the residents believe they are married, and since Paradisa doesn't believe in divorce, these marriages can last until someone goes home, whether the residents are still in love or not.
However, the castle never does anything without reason, and some things simply won't happen.
Pain or torture losses are some of them. While the castle often puts residents through hardships, it doesn't outright force pain on its residents; it merely puts them in a position where they might experience such things. As vicious as the castle can be, it will never make a resident feel pain or anguish on a whim, without any reason for it. When it comes to messing with people's lives on a one-on-one basis, it likes to tailor losses to the individual. Characters with grim pasts may be forced to re-live their darker days, but the castle will never foist random suffering on a character simply for the sake of suffering or angst. It likes to bring about change that makes the residents responsible for shaping how good or bad of an experience it was.
Additionally, what is keeping characters safe from random torture at the hands of their captor may be creepier than any random torture session: Paradisa has to “return” what it has borrowed, eventually. It wouldn't be nice to intentionally snap its toys, would it?