Eberron Campaign Guide
In dealing with the dragon marked houses, it is important to understand the nature of their power and how they gained it. It has taken the houses over a thousand years to reach the level of influence they enjoy today, and each of the following factors has played a role.
Unity and Wealth: These two elements are related. The dragon marked families were drawn together by their marks. This unifying factor (along with the mystical powers of the marks) gave these early guilds a competitive edge over independent artisans, and so they prospered. Over the centuries, each house has become quite wealthy, and many of them have used this wealth to eliminate rivals. House Cannith doesn’t care about a single independent blacksmith in Wroat. But if that smith somehow began producing warforged or remarkable magical goods and refused to join the Cannith guild, there’s a good chance that the house would arrange to have the smith eliminated, whether through a smear campaign or by hiring Thuranni assassins.
Rituals and Focus Items: Rituals didn’t appear out of thin air; every ritual had to be created, and many of them have gone through multiple stages of development, as new innovations lowered the cost and requirements to use them. Many breakthroughs in ritual magic were pioneered by dragon marked heirs tapping into the powers of their marks: For example, the Wordsmiths of House Sivis were the first to perfect the Sending ritual. Although most rituals can be used by any ritual caster, there are magic tools that can be used only by someone who has a particular dragon mark. Only those who bear the Mark of Storm can reliably control an elemental airship, and only those who have the Mark of Scribing can use a Sivis speaking stone. Eberron is a world in which magic is a part of everyday life. But some of the most vital parts of that magic—tools used in communication, transportation, medicine, and industry—can be operated only by the dragonmarked houses.
Training: After centuries of consolidation, most major trade schools are run by the dragon marked houses. An apprentice agrees to serve in a house guild in exchange for training—thus strengthening the control of the house guild over that trade.
Industry Standards: Whether it denotes a licensed business or a direct arm of the house, a guild seal promises a certain level of quality that the people of Khorvaire have come to rely upon. This is reflected by the standards for goods set down in the Player’s Handbook. A sunrod made to House Cannith specifications burns for 4 hours and costs 2 gp. If you go to an unlicensed alchemist, you might be able to get a sunrod at half the price—but it might last for half the expected time, or might not work at all. Of course, an unlicensed business could also exceed guild standards: There’s no way to know.
It is important to understand that beyond the dragon marks themselves, the influence of the houses is derived from over a thousand years of work—product development, propaganda, and the elimination of rivals. The houses have helped shape the modern world, developing rituals and techniques now taken for granted. Although the houses are neither omnipotent nor omnipresent, it’s always worth considering whether a business is a house arm, licensed by the house, or independent—and if it’s independent, whether it meets the standards people have come to expect, and what the cost might be for doing business with it.