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Page 137 of Rites of the Blood has alternate rules for learning thaumaturgical rituals on that allow the character to roll to determine how much time they must spend studying, with more adept thaumaturges having larger dice pools and a higher likelihood of learning more quickly.
Mastering a ritual requires an extended Intelligence +
Occult roll with a difficulty equal to the ritual level + 3. The total number of successes needed is equal to
the ritual level × 5. Each roll represents a week spent
analyzing, memorizing, and experimenting with the ritual,
although the character is free to do other things during
the same period if he can devote at least a few hours every
night to study. If the player dedicates his character’s full
attention to learning the ritual and doing nothing else
except feeding, each roll may represent a single night.
However, if the ritual is from an unfamiliar school of blood magic,
The total number of successes needed to
adapt and master a foreign ritual increases to ritual level × 10. However, the player may subtract the character’s total
number of dots assigned to all of her blood magic paths
from the number of required successes, to a minimum
of half the normal number of successes. This reduction
represents the extent to which greater fluency with one’s
own school makes it easier to adapt foreign rituals to it.