A slave is someone who is treated as property and forced to work. Slaves are often held against their will, and can be bought and sold across Districts.
Practice of slaveryEdit
Slavery is considered legal across the Barsburg Empire, with the slave trade being a highly profitable business. Both males and females can be sold into slavery. It is most common amongst the nobility of any District, who use slaves of different species- such as Trolls and Noel Mermaids. as well as humans, as trophies and pets.
In the series, slaves are used for a number of purposes, including domestic work, as pets and the most common form being battle slaves and child soldiers, who are used to fight. Slaves are required to wear chains until they are bought.
Many of them are very wealthy.
It appears that the slaves that resemble nobility the most (e.g. fair skin, blonde hair, and light green eyes) are the most expensive. Disguising a slave's appearance (via hair dye or other similar cosmetics) to increase the slave's price is illegal.
Identification EditSlaves are marked with a slave brand on their lower back. The scar left from it will last for life and is used to mark them as 'less than human'. It can also be used to identify a slave that has escaped.
The process of marking a slave with a slave brand is very painful for the slave. 
Characters who have been slaves Edit
Slaves, particularly battle slaves, are treated brutally. Throughout the Barsburg Empire it is legal to beat slaves unconscious- even with weapons, and deprive them of food. It is not considered a crime or a loss to kill a slave because they are at the bottom of the social hierarchy.
Battle slaves are trained from a young age to kill the military use them as a human weapon. Their reactions are tested by having to destroy a group of fast-moving orbs, and 'real combat' training is fighting and killing condemned prisoners. Their Zaiphon is also tested. They are given a four-digit number as opposed to a name. 
They normally wear a dark, tight jumpsuit, and no armour. They also wear Restraints, and a metal 'strap' across their chest where a leash can be attached.
The Imperial Army uses them to execute prisoners, and the Barsburg royal family forces them to fight each other in coliseums, or collects their body parts.
Un-bought slaves are prevented from entering privately owned buildings.This is because they would 'bother the other customers'. They can be identified by the chains around their wrists that can only freed by bought them.
Although slaves may have been common before the fall of the Raggs Kingdom, after the Raggs War, there was a huge surge in slave numbers as many of those not killed during the war were enslaved by Barsburg. As of the last manga chapter, a comment made by Carl seems to indicate that after the two-year timeskip, slavery in the Empire is on the wane.
- ↑ Razette was kept as a pet by a rich noble family, and a Troll-type person was a pet to Granne Barsburg.
- ↑ In Kapitel 27, Slave trader Carl was able to enter District 6 without the guards checking the contents of his cart, despite him hiding two wanted criminals in the back. They trusted his word that he had not seen the criminals.
- ↑ In Kapitel 27, the slave trader seen whipping a slave was wearing lots of gold, and Carl owns many carts and an aircraft.
- ↑ In Kapitel 27 Carl says that Teito will be very expensive due to the rarity of his green eyes.
- ↑ During the Hawkzile race, Carl says that blonde hair is a desirable quality in a slave.
- ↑ When Vanessa Antwort marked Teito with a slave brand, Teito cried and said that his back hurts, and The Pope said that Vanessa was tormenting Teito.
- ↑ Kapitel 39
- ↑ Kapitel 39
- ↑ Kapitel 39
- ↑ When he was a slave, Teito was called 2741.
- ↑ In Kapitel 27, a man says: "The one who is with you cannot enter. An un-bought, chained slave with bother the customers".