Humanity is a measure of how closely a vampire clings to the morality and values of mortal life, and consequently how well they are able to resist the urges of the Beast.

Since every Vampire was a human before their Embrace, their most natural response in resisting the Beast's feral, predatory nature is to cling to their humanity. This is generally represented by the strength of their Conscience and Self-Control, virtues common to Kindred and mortals alike.
A Kindred's humanity has a direct effect on the strength of the vampiric curse; those who lose ground to the Beast and lose their humanity find it more difficult to interact with mortals.

Humanity is universally adopted by the vampires of the Ambitiose Sanguine and their associated bloodlines. Some vampires however reject the mores of mortal existence and adopt an alien Path of Enlightenment, in which they learn or construct a wholly different standard of morality. These often incorporate different virtues, and instinct instead of self-control – and establish a very different relationship with the Beast. Replacing the morality of one's human life is a daunting task - not to be undertaken lightly, and generally impossible without the support of one who already follows the alternate path.

Humanity Ratings: A vampire's Humanity rating reflects how much of a character’s mortal nature remains despite the curse of the Vampire. It influences how well a character may deny their vampiric state, as well as how effectively it may pass for mortal. Sanguinaire's humanity system is loosely based on the World of Darkness Hierarchy of sins.

Humanity Ratings:
10 - Saintly
09 - Compassionate
08 - Caring
07 - Normal
06 - Distant
05- Removed
04 - Unfeeling
03- Cold
02 - Bestial
01- Horrific
00 - Wight

Reduction in humanity occurs when the Vampire commits acts that allow the inner-beast to exploit weaknesses in him/her. The Vampire is no longer human, and whilst mortals become corrupted when behaving a certain way, they do not have an inner-beast to keep in check, that will use any form of corruption to influence it's host and gain more control over the former humanity that still lingers. Below are the rule sets that cause humanity reduction. Each rating has a rule beside it. If a trigger is hit for the Vampire's current humanity rating, or a rating below it, a humanity loss will occur;

10 - Selfish thoughts.
09 - Minor selfish acts.
08 - Injury to another (accidental or otherwise).
07 - Theft.
06 - Accidental violation (drinking an innocent vessel dry).
05 - Intentional property damage.
04 - Impassioned violation (killing a vessel in Frenzy).
03 - Planned violation (outright murder, savored exsanguination).
02 - Casual violation (thoughtless killing, feeding past satiation).
01 - Utter perversion or heinous acts.