Generation

In Vampire: The Masquerade, Generation is a measure of the power of a Vampire.

Basic Mechanics
All kindred have a Generation attribute, which is ranked between 1 and 15, although realistically this attribute is rarely below 8 and except in absurdly powerful scenarios is almost never below 6. The generation attribute reflects a character's "distance from Caine". When a Vampire embraces a childe, that childe's generation is one step higher. So an 8th generation sire will have 9th generation childer.

Generation is the crudest measure of vampiric power, or more accurately, vampiric potential. Characters cannot use mind-affecting disciplines on vampires of a lower generation, and vampires of higher generation are more suspect to them. In addition, generation impacts how many blood points a character can spend at any one time, and the maximum size of their blood pool.

Power Gaps
In addition to the linear decrease in power with increasing generation, there are several distinct gaps in the generation system at approximately 3rd, 8th and 13th generations.

The thirteenth generation is the highest generation that can be played without the Time of Thin Blood supplement. Vampires higher than 13th generation have a very weak form of the curse of Caine - they have increased difficulty embracing childer, generally very long embraces (hours or days spent dead versus seconds for most Kindred), highly limited disciplines, increased blood costs for nearly everything. Oh yeah, and they can have kids.

The gap between 8th and 7th generation is more notable. 8th generation vampires (the lowest that can be played using standard rules) have a 'human' upper limit on their traits - they cannot have attributes above 5. 7th generation and below have higher limits. This also affects discipline usage - vampires of 8th generation or above are locked into a specific set of discipline powers, while 7th generation vampires can begin to create their own personalized abilities.

The final gap is around 3rd generation, although this is generally not modelable using Vampire rules. Apocryphally, the Antediluvians were inceptors - they could create new disciplines, notably clan-specific disciplines such as Obeah or Serpentis.

Changing Generation
Generally, the only way a vampire changes generation is through Diablerie. When a character diablerizes a vampire of lower generation, his generation decreases by one. There are some exceptions to this: Monty Coven's generation effectively became 5th when he diablerized Mithras. In addition, the Assamites developed a ritual to convert blood into an elixir for lowering generation when they were subject to the Tremere curse.

Generation has occasionally been increased, usually as the result of curse. The Assamite Tariq had his generation artificially increased to 13th (from fifth) by the Tremere Antitribu.

Vampire: The Requiem
Generation is not used in VtR, having been replaced with the Blood Potency attribute. Since changing generation has always been one of the most munchkin aspects of Vampire (notably with supplements such as Diablerie: New Mexico), the more flexible Blood Potency attribute provides a mechanism for both raising and lower a character's power and outlines costs for doing so.