Slaves are often freed if they show loyalty and hard work. Slavery is not illegal, but rare. Ethengars never use other Ethengars as slaves. Darokin has no slaves, but rather indentured servants. All slaves imported to Darokin are given a contract of a certain amount of years that they have to work before gaining their freedom.
Slavery is legal, but extremely rare.
Several Principalities allow slavery. Elves do not understand the concept. Freedom is taken for granted. Humans are often used as slaves as are any other creature. Dwarves from upon slavery.