Disciplines and the "Rules"

An error of omission has been brought to my attention and I would like to address this here. It is my ruling here that unless a vampire has clear experience or practice of a discipline (e.g., has training or long-term observation), he does not know what it can do, how it can be defended against or what the possibilities are. The ST may allow a willpower roll or not, or he may allow an int.+occult roll (or lore roll) or not, if he thinks it appropriate. Just because page such-an-such says "this" does not necessarily mean that it means "this" here. No one vampire is so old, powerful and experienced enough to know all the powers, levels, effects of each and every discipline but, all of them have the opportunity to learn them over the long term of their existence. It seems to me that this is consistent with the wider theme of personal horror and staving off the descent into the beast.