Arbiters

The four rules
1. Arbiters cannot quit making judgements, for that is the reason why they exist.

2. Arbiters cannot experience death, for that would bring them too close to being human.

3. Arbiters cannot feel emotion, for they are dummies.

The fourth rule was added in by Oculus after seeing Decim judge Chiyuki.

4. Arbiters may not work hand in hand with life, for that will ruin them.

Appearances
Arbiters can generally be male or female and can come in different shapes, sizes, and appearances. However, all of them appear to be inclined to wear uniforms. The uniforms mainly consist of a pair of black pants with black dress shoes and a matching black vest with a plain button up dress white shirt underneath and a red bow tie. All of the arbiters also have eyes with cross like pupils.

Job
Their job is to be given two humans who have died at the same time and judge them by having them play the game then place extreme conditions and lead the customers into thinking that they are still alive and that if they lose the game they will die. The arbiters prevent the customers from leaving and pass judgement on the customers by making the games extreme and seeing how the customers react when they believe they will die; in essence, they draw out the darkness in human hearts and pass judgement.

Hierarchy
Though not fully explored in the show, there seems to be a hierarchy established for the arbiters. It is clear there are certain bosses and people who are higher up than them. For example, Nona is clearly the boss and owner of QuinDecim and Viginti. Oculus is also clearly superior to the arbiters and even Nona, as he has stated he is closest to being God though it remains to be known what he means and he is never seen doing actual work. In episode 7, when Nona inquires Castra to give Decim two special customers, Castra says she can't because they are "marked" and need to be sent to a special arbiter. This would mean that there are certain arbiters that handle certain types of customers and are given these customers direct from the Information Bureau. In a sense, these arbiters are given more "difficult" humans or humans who are horrible, twisted, or have committed some form of grave and terrible sin. Since Decim wasn't supposed to get these customers, it would seem he is a lower level arbiter, possibly since he has less experience. It is unknown if an arbiter can become an arbiter who can handle these customers by gaining experience or if certain arbiters are simply given these jobs from the beginning (though it seems that these arbiters are more experienced so the first theory seems likely).

Existence
Their existence remains a mystery. Nona has stated that they are not human, do not experience emotions like humans do, and have never lived or died. They are even made to look like humans but are created for the specific purpose of judging humans. However, Decim appears to be an exception as Nona has implanted human emotions in him which, though at the beginning did not yet seem to appear or were not yet tapped, appear to be surfacing with him as Chiyuki criticizes him for drawing the darkness of human hearts and passing judgement, stating that it is not right for them to be doing that since humans are more simple than the arbiters think. They eventually surface, allowing him to feel sorrow and happiness after he puts Chiyuki through the ultimate test: being given the chance to restart her life by sacrificing another. When she refuses, saying someone else will suffer the loss of a loved one and breaks down crying and apologizing to her mother and being divided over wanting to see her and not wanting to sacrifice a life, he breaks down and the cross like pupils that all arbiters have in their eyes disappear, turning into normal "human" eyes, evidently signifying the fact he had become a "human" through his bond with Chiyuki and the empathy and feelings he felt for her (though his eyes quickly returned to normal after he went back to QuinDecim). They are usually commanded by those higher up than them. Strangely, despite the fact they are not living or dead, they are shown eating food in episode 7 and they also drink and can taste alcohol, though it remains unknown if food is a source of sustenance for them as it is for humans or if it is simply for their enjoyment, or even where the food comes from. Since items can be transported from the human world to the world of the arbiters like the Chavvot book Chiyuki liked, food could be transported from there but as to how or if it is even necessary to have food is unknown. It could also come from a different unknown source.

Bars
There are several floors in the building the arbiters work and each seems to contain a bar that one arbiter works. It seems only one arbiter is allowed though assistants, whether human or animal, seem allowed. The bars vary in style depending on who the owner is but all include elevators that link the bar to outside and a hallway with bathrooms. There is also a game-board that is used to select the game for the customers to play and what appears to be an extra room where the game is played. The floor for the extra room is equipped with a motorized platform to bring about what game the customers will play. The floor can also change depending on what game they are playing, possibly linking to other dimensions through the use of a remote control which is also used to manipulate the games.

Abilities
Each arbiter seems to possess their own set of unique supernatural powers most likely used to keep rowdy or disobedient customers in line. They vary though all arbiters are expected to know how to deal with alcohol and how to operate the bar to create games. They also receive the memories of the dead as a tool for judging them, though they can request for the memories to be sent to their assistants.

Information Bureau
In addition to traditional arbiters, there is the Information Bureau which collects the memories of the deceased, then compresses them and sends them to the arbiters to help with their judgement. Additionally, those at the Information Desk must check, deliver, and send certain customers to certain arbiters.

Known Arbiters

 * Decim
 * Ginti
 * Quin (formerly)