NOBLE HOUSES
All sidhe belong to a noble house, and have a Boon and a Flaw related to that house. Commoners may also belong to a noble house if they swear an oath of fealty to that house. Some houses will not accept commoner members, and some others may have very stringent qualifications that must be met.
More detailed information on the five main Seelie houses: Dougal, Eiluned, Fiona, Gwydion and Liam can be found in Noblesse Oblige: The Book of Houses. More detailed information on the three Unseelie houses: Ailil, Balor and Leanhaun can be found in Pour L'Amour et Liberte: The Book of Houses 2.
House Ailil (ay-LEEL): The most widespread and influential of the Unseelie houses. Members of House Ailil are political maneuverers without peer, although proud to a fault. House Ailil is detailed in The Shadow Court, The Book of Lost Dreams, and more extensively in Pour L'Amour et Liberte: The Book of Houses 2.
House Balor (BAY-lor): This Unseelie house supposedly originated from the offspring of a sidhe and a fomorian. They do not suffer from the Banality's Curse Frailty, as most sidhe, and are also more comfortable with cold iron than most changelings. They always suffer from some deformity (physical, mental, or social) that results from their fomorian blood. House Balor is detailed in The Shadow Court, The Book of Lost Dreams, and more extensively in Pour L'Amour et Liberte: The Book of Houses 2.
House Dougal (doo-GAL): A house with little political power, but probably the most practical of all the noble houses. Members of this house are usually excellent crafters, and smiths. They are able to weave Glamour into their undertakings, but suffer from some sort of handicap that may be compensated for with the use of some cunning bit of craftwork. Much more extensive information on House Dougal is in Noblesse Oblige: The Book of Houses.
House Eiluned (EE-loon-ed): The "house of secrets", these nobles are known for their mysterious natures, their love of intrigue and their skills with the Arts. Much more extensive information on House Eiluned is in Noblesse Oblige: The Book of Houses.
House Fiona (fee-OWE-nah): This house is the most popular among the commoners, and tends to be the loosest in its interpretation of tradition (at least among the Seelie houses). They are known for their exceeding bravery, and tendency to get involved in epic tragic romances. Much more extensive information on House Fiona is in Noblesse Oblige: The Book of Houses.
House Gwydion (GWIH-dee-on or GWUH-dyon): The most powerful of the noble houses, politically, they see themselves as the true rulers of the fae. They are able to divine the truth from lies, and have an unfortunate tendency to go berserk in battle. Much more extensive information on House Gwydion is in Noblesse Oblige: The Book of Houses.
House Leanhaun (lee-ANN-an or LEE-an-awn): The most artistic of the Unseelie houses suffers from a curse that causes them to age at an accelerated rate. They are able to retard this effect with Glamour, and reverse it with the Glamour gained from a terrible and forbidden form of Ravaging called "Rhapsody". House Leanhaun is detailed in The Shadow Court, The Book of Lost Dreams, and more extensively in Pour L'Amour et Liberte: The Book of Houses 2.
House Liam (LEE-am): The defenders of mortals, those of this house are those most likely to retain strong ties to mortals. They are known for their skill in affecting mortals with Glamour, but are dishonored, and considered oathbroken to the other houses. Much more extensive information on House Liam is in Noblesse Oblige: The Book of Houses.
House Scathach (SKA-thak, skuh-HAK, and SKY-ah have all been proposed): These sidhe are the only house to remain on Earth during the Interregnum en masse, and as such, reincarnate much as the commoners do. They are unaffected by Banality's Curse, but are unable to use the Art of Sovereign. They are silent and skilled warriors, but often fall into bloodlust while in combat. They are reviled by the other houses even more than House Liam, as they are not even considered to be true sidhe. House Scathach is detailed in Nobles: The Shining Host.
NOBLE HOUSES OF THE MERFOLK
All merfolk belong to a noble house as well. Which house a merfolk will belong to is largely determined by what sort of marine animal they have bonded with. The noble houses of the merfolk are detailed in World of Darkness: Blood-Dimmed Tides.
House Lorelei: The warrior caste of the merfolk, the fighting skills of House Lorelei are specially attuned to the water, but are fearsome on land as well. They tend to go into a frenzy when they spill blood though. Sharks, eels, skates, rays and the like are frequently the animals to which House Lorelei members are bound.
House Melusine: The house of scholars, House Melusine are the merfolk that have the most contact with the surface world. There's a good reason for this, as they are all bound to marine mammals or amphibians and must surface to breathe every six hours. It is generally House Melusine that is sought out when the merfolk need advice concerning the "dirtwalkers".
House Syrinx: The most plentiful of the merfolk houses and also the ruling caste, House Syrinx members are bound to most species of bony fish. They are able to command sea creatures, but must submerge themselves in water for at least an hour every day, or their will weakens.