While the manufacture of Slave Collars is a guarded secret their effects are powerful. Any human who puts on the collar, willingly or otherwise, will be compelled to follow the orders of their Master. Resistance to direct orders tears at the mind until the slave complies or is left a broken shell, bereft of personality and only able to respond to orders from their Master. A person broken by a collar does not recover if it is removed.
The collars do not provide absolute control though. The slave is free to interpret the orders given by the Master. For example a Master may issue the order, “Deal with that man.” One slave may interpret those words as an assassination order, while another may interpret it an an order to make the offensive person leave. The slave collar also affords for planning, if more specific orders aren't provided. Using the above example, a slave intending to kill a target designated by their Master may wait until a time when the victim is alone. There is no “punishment” by the slave collar since the intent to carry out the order is present.
It should be noted that, if the slave cannot understand an order, there is no compulsion to carry it out. Slaves who can't understand their Master's language or are deaf would require special handling.
Collared slaves are able to collar others who then become their slaves. The new slave would follow the orders of the first slave, but would also defer to the first slave's Master. If the first slave and the Master issue conflicting orders the new slave will follow the orders of the Master.
It appears the collars may not be entirely effective on races other than humans. Catgirls are only vulnerable to the effects of the collar when weakened (in Yamamaya's case, by hunger). Elves even when collared against their will possess the mental fortitude to retain their personality. It is unknown what effect, if any, the collar has on dwarves, orcs or other sentient races.
The Slaver's GuildEdit
The Slaver's Guild is the largest dealer and purchaser of legal slaving in the Middle Kingdom. Slaves may be sold to the Guild to pay off debts or when a family lacks the resources to care for them. As a result the majority of slaves available from the Guild in the Middle Kingdom are skilled in domestic work.
The Guild also undertakes expeditions to areas outside of Middle Kingdom to recruit slaves, though in this case, since the Guild is no longer under the jurisdiction of the Middle Kingdom will resort to kidnapping or other less legal tactics. Chimei and Yamamaya were recruited by these expeditions.
The Church of the Seven AngelsEdit
The Church appears to make use of the slave collars when executing arrest warrants as a means to control unruly prisoners. Their use of slave collars does not appear to be public knowledge judging by the reactions of the hero.