Official GSIV document...

Houses are player-run organizations recognized by the local government as a private cooperative. GemStone III players can have their players form Houses and build up memberships to enjoy many benefits. These include such incentives as loan services, storage facilities, engraving a custom coat of arms, political objectives, roleplaying opportunities, private and secure meeting areas, private property ownership, and the ability to rent the ability to rent the Gladiatorial Arena to hold privately sponsored Games and to reap the benefits therefrom.

Houses are established by players using the rules outlined in the official document. Requirements for leadership include being a dedicated player who wishes to put forth the effort to setup, maintain and rule the house structure. The player should also be a good roleplayer because many of the activities involved in the house system are best played in the strict guise of your character.

Argent Aspis

Beacon Hall

Brigatta

Arcane

Twilight Hall

Helden Hall

Silvergate Inn

Rone Academy

House of Paupers

Whitehaven

Willow Hall

Sylvanfair

Obsidian Tower

Phoenix

House Sovyn

House Vaalor

Moonstone Abbey

Windsor Hall

Chesylcha (closed)

Mistydeep Manor

House Ravenwolf

Moonshine Manor

Ardenai Temple Knights

20th Regiment, Guardians

House Onoir

House of Serenity

Canid Keep

Second Militia

Starlight Gardens

Cairfang Manor

House of Eyre

House Talongard

Genteel Society House

Timberline Lodge (closed)

House of Rosemoon