The Ostlers' Guild has a monopoly on breeding, caring for, and selling horses for profit. This monopoly extends to ponies, mules, and donkeys. Most master ostlers work as stablemasters, providing shelter, food, and water for horses owned by others. The majority work with innkeepers as free or bonded masters, but others are bonded to major nobles, legions, and fighting orders.

An all-around master ostler has the skills of livery stable manager, equine veterinarian and farrier, tack and saddle maker, and stud breeder.

The typical stablemaster is something of a jack-of-all-trades, but others in the profession may choose to specialize. Farriers look after the veterinary and physical needs of horses, including shoeing them. Tackmakers make and repair horse tack and saddles. Studmasters run stables that specialize in the breeding and training of horses.

This article describes the organization and activities of the Ostlers' Guild as well the guild's place in Hârnic society. Details are given for each of the disciplines, including caring for a horse and common ailments and treatments, as well as other information useful to running teamster PCs or NPCs.