Most sorcerers attribute their magical prowess to a supernatural ancestor, such as a celestial, dragon or fiend. A few have no special heritage, and might be the result of exposure to magical effects. Most sorcerers discover their powers during puberty, although some develop earlier, and a few later in life (the latter is more prevalent among those of common blood). Some scholars believe that sorcerers are becoming more numerous, though why this is and what it foretells is a matter of debate.
Sorcerers fill many of the same roles as other arcane casters, providing magical support to endeavours both civic and military. Some sorcerers act as advisors, but most prefer occupations that utilize their specialized magic or their forceful personalities. Sorcerers fit well in positions of authority, as they are naturally talented at persuasion: depending on their temperament they might use motivation or intimidation to get what they need from their followers, and back up their words with magic.
Most sorcerers prefer to be among people. Many are flamboyant with their magic and their dress, leaving no one in doubt of their puissance. Others are, if not humble, at least affable and convivial. A sorcerer who turns her powerful ego to intimidating and subjugating those around her is a terror to behold. A few sorcerers shun attention. In regions where sorcery is mistrusted, their natural glibness allows them to deflect suspicion through disguise and deception.
Sorcerous ability among humanoids can usually be traced back to a supernatural ancestor. Legends are filled with dalliances between outsiders and mortals: from angels who fall in love with mortals to devils who trade in favours of all kinds. Osirian elementalists trace their lineage back to genies both fair and foul. Dragons — the embodiment of strength and magic — are frequently known to consort with humanoids, and many sorcerers believe they have draconic blood. A few sorcerers exhibit traits reminiscent of aberrations or undead, although how such miscegenation could occur is a matter best left to the scholars.
Favoured Regions: Areas that have seen a great deal of magic over the years tend to produce more sorcerers than their neighbours. Many sorcerers from Geb allege descent from undead bloodlines, a claim rejected by many traditional scholars. Neighbouring Nex also has a large number of sorcerers. Many scholars believe the magic that decimated Nex now infects its people; others whisper that the lords of Nex have found a way to create sorcerers by means of the fleshforges. Varisia, once the centre of a magical empire, produces many sorcerers — especially among the native Varisians — despite its sparse population. To the north, the Worldwound births more than just monsters, as sorcerous ability occurs with greater frequency among the refugees of Sarkoris, as well as those who defend its borders. The largest concentration of sorcerers is found on the Isle of Hermea; it is said that the draconic lord of the isle nurtures such abilities among his subjects.
Hidden Reserve (Su): Some sorcerers raised on the Isle of Hermea do not call familiars like others from the mainland. They instead focus their development on harnessing their inner reserve of magic, for use in times of need. This ability replaces the summon familiar ability.
Starting at 1st level, a sorcerer with this ability can call upon a hidden reserve of magical energy to cast additional spells. This reserve can be used to cast any spell the sorcerer could normally cast, but the sorcerer is fatigued after the spell is completed. If this spell is of the highest level that the sorcerer could normally cast, the sorcerer is exhausted instead. This ability cannot be used while fatigued or exhausted. It can be used a number of times per day equal to the sorcerer’s Charisma bonus.
Source: Pathfinder Chronicles: Campaign Setting (Page 50)