How Anchors Shape the Form of Spells
Two factors influence the shape a spell takes. The aspect of the motes paid as the spell's Price is the dominant one, and even a fool can tell a spell cast with solar essence apart from a spell cast with water essence. However, the Anchor used also influences the shape of the spell through the required rituals and the kinds of spell they can support.
Spells are learned for a specific Anchor. An XP surcharge must be paid to learn a new variant of a spell which uses a different anchor, and long study is required to convert a spell to using a different Anchor. As a result, in the short term most sorcerers are tied to their Anchors and a magician who needs his staff to cast spells can be disarmed and his threat greatly reduced.
Allies (and similar backgrounds, like Mentor)
When a sorcerer calls upon Allies to cast a spell, she is entrusting the spell to other empowered beings - most commonly spirits. Sorcerers who commonly anchor spells in demons are called demonologists or infernalists; sorcerers who anchor them in ghosts are referred to as necromancers. The beings in question must be capable of producing that effect; one cannot call on elementals to interact with the underworld. The Price of such spells often includes Resources offerings, blood sacrifices of Health Levels (or human lives for more powerful spells), and veneration.
The precise nature of the ritual behaviour and actions depends a lot on the entities in question. Demons ask for all matters of strange and often unnatural behaviour based on their alien drives, the Dead ask for veneration and prayer (as do gods), while elementals are often the simplest to handle and such things are based on the wants of the elemental who leads the court the sorcerer has a contract with.
The power of the Ally limits what spells they can anchor. Demons of the First Circle can only empower the simplest of spells, demon lords can empower the Sapphire Circle, while those who entreat with the demon princes can perform Adamant miracles. Similar limits apply to gods and the dead. Elementals are not so constrained, for their numbers and the power of the dragon lines they can draw upon allow even the mightiest spells to be performed if one has enough elemental servants.
The Ally's power must be able to reach the sorcerer in some way, or they must carry a symbolic token of the alliance. Demonologists load themselves up with trinkets of the demon realm to invoke its fell power in Creation, while necromancers dress in the trappings of death and carry ghosts bound in china jars.
Artefact
Many sorcerers consider artefact-anchored spells to be the most pure expression of the sorcerer's skill. In such spells, it is only the sorcerer's will, and the object that they are using to channel and shape their desires. Many of the most basic spells in a common sorcerer's arsenal use an artefact weapon as an anchor, and that is why the image of a sorcerer so commonly features their magical staff or their enchanted blade. In the case of Emerald Circle Banishing cast through an Artefact weapon, for example, the sorcerer literally orders the demon to return to hell while threatening them with their weapon. Many blades and armour made for sorcerers incorporate hearthstone sockets so that the sorcerer may draw power from the gems without having to fumble in a pocket.
Other sorcerers take a less direct route, and instead call on an aspect of the Artefact such as its legendary history or its construction. Thunder Wolf's Howl cast through a soulsteel blade makes the weapon itself scream with such force that men are sent flying, while many Dragonblooded sorcerers cast Death of Obsidian Butterflies by calling on the sword used by countless ancestors until the air itself is filled with the flapping memory of endless cuts and stabs. Devonian sorcerers in particular are infamous for designing artefact mechanisms designed to synergise with one spell or another, such as the infamous Orrery of Va Nelba, from which the sorcerer-king of the land could perform Cast Beyond the Veil of Time by adjusting it so the area no longer appeared in the future it displayed. Demonologists are notorious for their demon-wrought tattoos filled with malicious power that they can call on.
Obviously the sorcerer must have the artefact to hand to make use of it. This is why sorcerers are customarily stripped and searched when they are imprisoned, for fear of an unknown mystical amulet or magical brand they may have hidden on their person that they may use to escape. Wise guards never assume that they have found everything, for in Immaculate stories there is a tale of a wicked sorcerer who hid a demon in his stomach that kept his magical ring safe.
Backing
When a sorcerer anchors a spell in their Backing, they rely on symbolic logic and the authority of the institution. Because they are lord of this land, they can call on the earth itself to rise up and the rivers to flow with blood. Because they are a factor of the Nexan Guild, their knowledge of value lets them turn lead into gold through financial sorcery. Because they are an exorcist of the Immaculate Order, demons flee their presence. To do this, the sorcerer must explicitly invoke the authority and wear the trappings and garb appropriate to their position.
Certain spells are linked to a specific institution. For example, the sorcerers of the Realm and the Immaculate Order call directly on the authority of the Scarlet Throne - and this worries them greatly as it sits empty, for they worry that their spells will become unreliable. Other spells, by contrast, call upon a role. A spell anchored in a king's position does not care which throne the sorcerer-king sits upon; only that they have the power to command the land.
Breeding (and Lineage)
The breeding of the Dragonblooded is a force of mystical potency. The blood of dragons flows in their veins, and in the High First Age countless spells were invented by Terrestrial sorcerers that were anchored within the draconic force within them. Spells which use this always have an elemental aspect and must be cast with the Dragonblooded's own essence. Such power forms draconic iconography naturally, and is particularly efficacious in areas that harmonise with their element. Alas, the bloodlines of the Terrestrials have withered and they are no longer what they once were. Many spells anchored in Breeding are unusable by much of the Terrestrial Host.
Or at least they would be, if it were not for sorcerous lineages.
Lineage is effectively a pseudo-Background, which only exists for the purposes of anchoring spells and extends Breeding. Rather than blood purity per se, it instead is a measure of the accumulated contracts, oaths, and mystical potency that builds up among families where many generations practice sorcery. It is mostly seen at a family level among the Dragonblooded, but a few bloodlines of mortal sorcerers and incestous Lintha sects have generated it. More commonly it instead builds up down chains of mentor-student relationships. The Sidereal Exalted maintain chains of teaching which pass through Chejop Kejak that reach all the way back to the First Sorcerer, though those who are his personal students are less potent than those who have learned from those who have learned from those he taught.
However, since one's Lineage rating increases Breeding for sorcerous purposes, Dragonblooded from families of sorcerers can call upon rituals and spells despite having weak blood. House Ledala is famed for this, and some of the families within the House try to ensure every member is a sorcerer as to strengthen the lineage of all of them.
Cult (and other group backgrounds, like Followers and Command)
While Backing draws on a greater institution (even when a king performs it), Cult and other such backgrounds draw on the adoration and power entrusted to the sorcerer by others. Sorcerers who rely heavily on Cult are known for being egotistical even by the standards of magicians, and they are not humble men normally. It is through the obedience of others and their willing subjugation to his will that he subjugates the laws of nature. Other sorcerers remain a little more grounded, and anchor the spell in the actions of their followers in great prayers or by having their servants perform geomantic procedures in carefully chosen places across the land.
Just as a purely incidental note, these backgrounds can be emulated by the ritual sacrifice of human lives. Many necromantic spells are made so that instead of sacrificing loyal servants, one ritually kills one's foes. The following reanimation of their corpses is considered an elegant way of recycling.
Familiar (and other familiars, like Demonic Familiar)
Spells anchored in a familiar empower the creature to carry out the orders of their master. Most famously, Infallible Messenger is commonly taught for Familiar, and the creature in question bears the sorcerer's words to their target. This may mutate the creature heavily, such as a hawk familiar becoming a garda-bird-like creature for Flight of the Brilliant Raptor. Some sorcerers even assume properties of their familiar through magic, such as taking on their tiger's claws with Wood Dragon's Claw, or turning into the animal outright with the Skinchanger Rite.
More mystically potent familiars blur the lines between allies and familiars. A sorcerer with a demonic familiar of a blood ape may use it was if it was an allied demon - and with more potency, for it can feed directly off his essence due to their contract. Some sorcerers take unholy glee in empowering their demonic or spectral servants so that onlookers fear the power of their familiar - and so fear them even more.
Manse & Demesne
The first great split in human sorcery was born of the fact that while one can anchor spells in a demesne, one cannot in a manse. The mystic power in a manse is already sealed down, calcified into the production of hearthstones. Devonian sorcerers have long considered this to be the best use for the dragonlines, for the hearthstones may be used by a sorcerer to cast spells that require essence of aspects other than their natural one. Hearthstones can be used to pay the mote Price of a spell - and Resources costs too, for they are gems of great value as well as mystically potent. It is said that in the High First Age, their skill with the design of manses was so great that the hearthstone was nearly inert and could last a century or more until its power escaped. Such days are long past, and most modern hearthstones bleed their essence out until they are dry. Fire hearthstones are hot to the touch, while the hearthstone-like gems hewn from Malfeas' flesh sicken those who carry them with toxic Green Sun Wasting.
By contrast, Salinian sorcerers typically consider manses to be a blight on the natural essence of Creation, causing it to stagnate, and they favour the use of untapped demesnes as places of power. Rituals anchored in a Demesne channel power from the land itself, and likewise may be used to cast spells with the essence aspect of the sacred space. Salina preferred to honour the land and treat it in thematically appropriate ways, but a sorcerer might as easily rip the power from the land through the force of their enlightened will. There is a limit to how far one may channel the power of a demesne, though, and unless one is standing close to a dragon line one may not anchor a spell within a demesne unless one is within a few miles of it.
Purely as an academic note, Silur took a neutral position in the entire argument, though practically speaking she tended to favour manses due to the increased flexibility that easy access to hearthstones gave sorcerers. However, Silurian sorcerers did hybridise the two designs to create manse designs that instead radiated their power in synthetic dragonlines to specially made artefacts - a compromise which pleased neither party.
Resources
Alas, Resources are too ephemeral and fleeting to anchor a major working in. Instead, Resources components can be part of the Price of certain spells in addition to mote costs. This is particularly common in spells anchored in patron spirits who ask for sacrifices for their blessings. Those who cast Total Annihilation through an alliance with the Green Sun must sacrifice a priceless emerald the size of a chicken's egg as a vessel for his blighting power. Many less spells cost vast sums in exotic reagents to cast, which is another reason that sorcerers have a reputation for greed.
Whispers
When the Black Nadir Concordat plundered the graves of the Neverborn, they bathed in their cosmic filth and contaminated their very souls with the putrefaction of murdered titans. This rot is full of dreadful power, and may be invoked by practitioners of the Black Art. Unlike almost all other Backgrounds, Whispers are not committed to sorcery. One can take everything one wishes from Oblivion, and it will only grow greater.
Spells invoking Whispers automatically contaminate the nature of the essence used to cast it to "Necrotic". The rituals for such spells are dreadful and profane, full of glossolalia, mad logic and the terrible anti-mathematics of the Void. Sacrifices of Resources care little for the actual goods being destroyed - Oblivion just wants valuable things unmade. Human sacrifice is also commonly required. Spells cast through Whispers are twisted to fit the aesthetics of the Labyrinth - Raising the Earth's Bones pulls up a wall of literal bloody bones, dragged from mass graves across Creation, while the butterflies in Death of Obsidian Butterflies are not glass, but instead tiny fragments of the Void which only look slightly like the butterflies of the living world.
