Além da linha que você mencionou, eu li o livro para improvisar e descobri essas partes ...
Feitiçaria de sangue, página 13:
Rather than enumerate every possible ritual or miracle, this system breaks the Ritual Disciplines down into Themes that are then combined to produce new effects on the fly—a Sanctified master of the Destruction Theme may attempt any miracle he can think of using that Theme, without the need to buy them separately. There is still a reason to buy rituals with Experience, however. Rituals the practitioner “knows” are easier to cast and more potent than improvised ones.
Os rituais aprendidos são mais fáceis de conjurar e mais potentes. O sistema é explicado mais tarde.
Página 16:
The dice pool used varies by Discipline and by whether or not the ritual is already known to the ritualist. Improvised rituals always use the same Attribute + Skill combination, adding the character’s dots in the Theme used. Learned rituals, however, use Attributes and Skills according to the following table, added to the Theme in use.
Os rituais melhorados e aprendidos usam diferentes conjuntos de habilidades. (não uma vantagem para rituais eruditos tu)
Página 17:
Success: The ritual succeeds and takes place as described by the player. Excess successes are lost for improvised rituals, but they may be assigned to the ritual factor or factors of the player’s choice for learned rituals.
Excesso de sucessos são perdidos por improvisação rituais. (Então os aprendizes podem ser mais potentes se você tiver sucesso em excesso)
Example: An Acolyte ritualist is performing a rite to immunize her coterie from the effects of Vinculum. This is a 18 Blood Sorcery Protection •••• effect, so the initial target number of successes is four. Making the effect last until the next sunrise adds three successes to the target, and affecting all three members of the coterie adds another two. The final target number is nine. She rolls Presence + Stealth three times, and gains ten successes. Because the ritualist knows the rite, rather than improvising it from her knowledge of Protection, her player may then spend the extra success. She chooses to increase the duration to a month.
Há diferenças mínimas entre improvisado e aprendido e eu não consigo ver nada que comprove Os rituais improvisados são mais lentos ou Os rituais aprendidos são mais fáceis de conjurar partes.