The hardest thing for any neonate to grasp is the fact that The Sabbat are not evil. I've seen evil and believe me The Sabbat are not it. Cruel? Yes. Violent? Yes. Fanatical? Certainly. But evil? No. To understand this you must understand what The Sabbat are about, their beliefs their goals. Yes, unlike The Camarilla The Sabbat do have goals.
Most important amongst these goals is the prevention of Gehenna, or at least the preparation to fight when it comes. Not so different from my own beliefs. This is why they fight with such fervour. What is any sacrifice compared to the end of the world? That is why they fight The Camarilla so hard. They believe you all to be tools and playthings of the antediluvians. A large pool of food and troops for them to use in their eternal Jyhad.
This is why the Sabbat seem so anarchistic and destructive to us. They do not believe in control by elders. This includes the blood bond which they can break with their ritual of the vaulderie of which I will speak more later. They do have leaders and a hierarchy, but this is more open to meritocracy than The Camarilla's geritocracy. Neither do they believe in humanity. They rejct it. Say they are more than that. Predators, the highest form of life on the planet. That is why so much of their behaviour seems evil to us. We look upon them as still 'human' when they are not, and neither are we.
The Sabbat is largely made up of 'defectors' from other clans and sects. All 13 are represented but as 'Anti-tribu' or anti-tribes. The leader clans of the Sabbat are the Lasombra and the Tzimisce. The Lasombra have many redeeming features to them, they are able, principled leaders but the Tzimisce are rotten to the core. Foul experimenters they can twist and pulverise flesh to their own ends making mockeries of man, beast and kindred alike. Within the Sabbat is a sub-sect of warriors called The Black Hand. They appear to be an elite set of shock troops though their use seems to follow no clear rhyme or reason. Also within the Sabbat are its inquisition, who I have worked with before. The Inquisition of th Sabbat is dedicated to rooting out infernalism and destroying it. This is almost as important to the Sabbat as their preparation for Gehenna. They abhor the agents of true evil.
The Sabbat appear to be structured in a way similar to the Catholic church. All leaders are mere proxies until the return of Cain though. Something I myself adhere to. I know of Archbishops, bishops, priests and templars though the structure suggests that the satire goes all the way to the top. Perhaps some kind of 'dark pope'.
The Sabbat emerged from the Anarch revolt and probably the spread of influence of the Assamites. When some Antediluvians were lost the Lasombra and Tzimisce joined the Anarchs and the Assamites made deals to support their cause. Eventually the Camarilla won out over the Anarchs and a peace was signed at the convention of Thorns but many refused to surrender and many Assamites wished to escape the curse. This was the beginning of the Sabbat.
Le exangue and their leader Danton also refused to sign the Convention, but did not like the way they saw the Sabbat going and made their own path. Fighting both Camarilla and Sabbat and surviving takes power and cunning and is to be respected. Their press makes them appear far worse than they are, and afterall, as my credo goes.. "Whatever it takes".
The Sabbat are highly ritualistic, this gives them many opportunities to bond and to perform their Vaulderie ritual in addition to others. They mark many events in a uniquely vampiric way. They are a true vampire society finding their own ways. The only Sabbat rituals I have true knowledge of are their creation rites and the Vaulderie. Most know of the creation rites, the burying of newly embraced kindred so that they may fight their way to the surface so I will only speak of the Vaulderie.
The Vaulderie is the means by which the Sabbat both break personal bonds and create group bonds. Where as the Blood Bond is an intense and burning passion of love for the bonder the Vaulderie is more like an intense feeling of comradeship, fellowship and friendship. It takes at least three to perform it, all participants share blood in a bowl or recepticle and then all drink.
The Sabbat are not mindless fiends. They can even be allies against The Infernal. The only ones within them truly worthy of our utter loathing are the Tzimisce. The others should be respected adversaries. Do not underestimate them.
Elders fear this power greatly and have decreed a death sentence on all those 'corrupted' by it. I have seen Magi 'exorcise' this power from one of its users and I have to wonder at the true nature of this power. Anything anyone can tell about it would be gratefully recieved.
The Tzimisce
These fiends almost live up to the image The Camarilla tries to portray of the Sabbat. Fiends, with total disregard for the sanctity of life and unfettered by any consideration of decency or morality. When as other parts of the Sabbat take the mores of animals as their cue these fiends are far more like a cruel and curious little boy. Plucking the wings off flies to see how they cope. The Tzimsce can go further though. They can blend and manipulate flesh to create new creatures and to form their bodies into weaponry not seen anywhere else. If your fief begins to experience disappearances, or animal attacks, suspect a Tzimisce.
The Lasombra
The 'Ventrue' of the Sabbat, with some differences. Their politics may be Machiavellian and their scheming no less potent than that in the Camarilla but the Lasombra CAN be reasoned with. Far in their past they were responsible for the creation of the Kiasyd line. A blend of Faerie and Vampire physiology that while peculiar holds great power. The Lasombra are cultured after a fashion and strong in leadership and belief. They always put me in mind of the the classic sleek black witches cat. Lasombra can control the Shadows and after seeing what my Kiasyd friend and companion Joshua can do with this power I would be wary.
The Brujah Antitribu
The others are just clown-house mirrors of their Camarilla clans, but the Brujah require special consideration. They are still our brothers, our family despite being 'Black sheep'. They are used as we are used by the Camarilla, as shock troops, as a 'sea defence' against anything that threatens the leaders. Try to remember that they are the same as us and do not discount them as evil.
City Gangrel
These appear to be an offshoot of the main gangrel, rather like the difference betwee urban and rural foxes. I have only heard the term and do not know of any other differences.
The Leader of the Sabbat is entitled the Regent, something like the Pope in the Catholic church, the Regent rules for Cain untill his return. This is in part why I titled myself 'Regent' when I took power in Hampshire as we share this belief. I have no intel on the current Regent.
Below the regent are cardinals who are largely autonimous. They are somewhat like the Justicars of the Camarilla, each having an area to oversee.
Below the Cardinals are the Prisci. These act like a council as far as I can tell. Voting on and vetting plans and issues.
Below this are the Archbishops, these are somewhat analagous to Princes in the Camarilla.
Bishops fall below this, somewhat like Primogen but leading all clans within their section.
Sabbat priests are somewhat like whips or coterie leaders. They are responsible for low level 'fireteam' leadership and the spiritual wellbeing of the packs. They are knowledgable and have much reading, maintaining the traditions of their sect as they do. Try to capture them rather than kill them outright.
At present I am only aware of a few factions within the Sabbat.
THE INFERNALISTS
These seem to be gaining power and coming out of hiding to even leading positions in the Sabbat sect taking many under their sway. We must assist the Sabbat in purging their number of this vile breed, I am certain they are responsible for many of the Sabbat's excesses.
THE INQUISITION
Steadfast and stout kindred all. They can be cruel and unrelenting but they get results. The Inquisition opposes the Infernalists within the Sabbat sect and destroys them. If alone, and pursuing an infernalist this faction can be trusted to assist you. I have worked with them before.
THE BLACK HAND
I have only ever met them in the capacity of shock troops and have killed many of their number. On their bodys however I found evidence of some mystic beliefs and a subtly different version of the Book of Nod to the standard Sabbat one.