The Masquerade

The "Masquerade" refers to the tactics those who are members of the Camarilla go through in order to hide from humanity. During the Inquisition in the Middle Ages, many vampires (who until then saw little reason to disguise their presence and power) were destroyed and most of the major clans divised the "Masquerade" in order to avoid such future "disasters". Beginning characters are always Camarilla as it provides many elements which make gameplay easier and also help maintain a "base" from which people can learn about character development (instead of being dropped right into the deep end!)

For example, there are "rules" and "institutions" which mean that most will find themseves subordinate to either their "Sire" (the one who made them a vampire), to a Primogen (local clan "leader") or Prince (leader of the local vampiric area). This means you need not worry about irritating little details - such as clan politics and such - so much and focus more on developing your characer.

However, because of this, there is a very unbalanced system of power - which White Wolf carefully constructed in order to create intreige and conflict. for example, Princes are rarely "elected" - they just happen to be the most powerful in the area - and corruption is really the only way in which most manage to have any influence upon others. One vampire may not be totally acting for their own benefit and there is always the fear that more old and powerful vampires (some can be a million years old and more) are in fact orchestrating much of what happens. This air or paranoia and suspicion dirves a lot of what happnes in games, particularily if they take a political lint. One of the most dramatic shows of this can be when a "bloodhunt" is called - this is when the Prince declares that a particular Vampire has broken the rules of the Masquerade and so should be hunted down and killed - and such an event can take up a good few plot sessions.

Traditions

First Tradition
The Masquerade

Thou shalt not reveal thy true nature to those not of the Blood. Doing so shall renounce thy claims of Blood.
A breach of the Masquerade is the most serious crime a vampire can commit, and one of the easiest for a prince to fabricate if she wishes to punish an enemy. Depending on how strictly the prince upholds the Masquerade, anything from using vampiric powers in public to having moral friends may constitute a breach.

Second Tradition
The Domain

Thy domain is thy concern. All others owe thee respect while in it. Non may challenge they word in thy domain.
A tradition invited by the Camarilla? Think again. The Tzimisce of the Sabbat began this one. With their strict ways of keeping their domain respectful, as well as extremely private, it should be no surprise. "Domain" inclues not only havens, but hunting grounds and bases of power.

Third Tradition
The Progeny

Thou shalt sire another only with the permission of thine elder. If thou createst another without thine elder's leave, both thou and thy progeny shall be slain.
Most princes insist that they are the "elder" of this Tradition's wording and, as such, require that any vampire wishing to create a childe obtain their permission before the creation.

Fourth Tradition
The Accounting

Those thou create are thine own childer. Until thy progeny shall be released, thou shalt command them in all things. Their sins are thine to endure.
In other words, watch your kid, make sure they don't get their rumps in a roast, or it'll be your rump that's roasted.

Fifth Tradition
The Hospitality

Honor one another's domain. When thou comest to a foreign city, thou shalt present thyself to the one who ruleth there. Without the word of acceptance, thou aren't nothing.
Some call this the Tradition of "politeness"; Knock before entering. The Tradition, simply put, a vampire traveling to a new city should present herself to the prince or other elder in charge of that city. This Tradition was also invented by the Tzimisce, mainly amongst their clan where a newly embrace, or newly arrived Fiend has to present themself to the Voivode, a Tzimisce ruler.

Sixth Tradition
Destruction

Thou art forbidden to destroy another of thy kind. The right of destruction belongeth only to thine elder. Only the eldest among thee shall call the blood hunt.
Turmoil in the streets is considered by many to be one of the best coverings for kinslaying, but the punishment for getting caught is still severe. The only time when a vampire ranked lower than an elder might receive sanctioning to kill another is during a blood hunt