As I was plotting out the vampires for my campaign city I realised that most of them would probably have a Ghoul or two (or three or even more) but that I had no idea what the typical retinue would be like. Is there any indication in the rules as to an 'average' number of Ghouls there are per Vampire in a city? Does it vary much by clan as well?
I've heard that in Camarilla cities there is generally an imposed limit of one Vampire per hundred thousand mortals but is there a similar limit on the number of Ghouls, and if so, does it differ for Anarch and Sabbat cities?
Thus in a city of a million humans there would be, on average, ten Vampires and ??? Ghouls.
I'm happy for an answer from any of the editions of Vampire the Masquerade, from other sourcebooks, or even a simple mention in some (official) fiction. No guesswork please, but a suitably mathematical extrapolation might be okay provided the numbers are reasonably justifiable.
Best Answer
There is no complete, canon answer.
At least so far as I have found, no source provides an average number of ghouls per vampire or per city. It is not mentioned in Ghouls & Revenants, and if there were to be an official answer, I would expect it to be mentioned in that book. More than that, as Baskakov_Dmitriy mentioned in a comment, there are several variables that would affect it city to city. The most significant factor would be the Prince (at least in Camarilla controlled cities), as creating a ghoul is a technical violation of the masquerade and thus requires the Prince’s consent (so long as the Prince is powerful and respected enough to enforce it…). This means that there would be high variability from city to city and situation to situation. In statistical terms, this means that even if we had an exact mean, it would have a high standard deviation.
Furthermore, on a meta level, the needs of the plot and the type of game being played might affect the number of ghouls that actually appear in a meaningful way even if the storyteller declares that the world itself is officially sticking to whatever the average may be. In an “on-the-run from powerful enemies” type games where the main players move often, ghouls might appear very rarely. In a more stationary, politically focused games, ghouls will probably appear a fair bit, though mostly as background characters. But in a “Ghouls” game as laid out in “Ghouls and Revenants”, Ghouls are likely to be extremely common as most PCs and their peers will be Ghouls.
Slightly more than 1 per vampire is probably a good estimate
This essentially is a guess, but I think it is a fairly reasonable guess. Ghouls are so useful for handling business during the day, providing protection during the day, and providing cover for the masquerade that most vampires will want at least one. (Other non-ghoul retainers can also provide most of those benefits of course, but between the power of the blood bond, the enhancements to the ghouls’ abilities, and the lack of need to protect the masquerade from the ghouls, ghouls generally make better retainers). On the other hand, the law of diminishing returns hits rapidly for a resource such as ghouls. In other words, having one ghoul is a huge benefit, having two ghouls is only slightly better than one, having three ghouls is only very slightly better than having two, and with all the maintenance involved having four ghouls might be more trouble than it’s worth for most vampires.
If all of those assumptions are correct, then I would conclude that most vampires will have one ghoul. Not all will of course. Some will not have the clout to get the permission from the Prince. Some will not have a desire for a ghoul, especially among the Gangrel. But the sizable minority that do not have a ghoul are likely to be roughly balanced by the number of vampires that maintain more than one ghoul.
Altogether, I think that on average, a city will have just slightly more ghouls than it does vampires.
Just to emphasize though, that is both an educated guess and subject to wide variability even in settings where it is true in general. Sabbat held cities will hold fewer ghouls as Ghouls & Revenants states that the Sabbat make less use of the Ghouls. In times war, Ghouls may well be produced en mass to fight for their masters. Etc.