ST Note: Herein are the revised rules for learning Necromancy and Thaumaturgy paths and rituals. Some aspects of them stand to reason for other disciplines too, and may be adopted in a more global sense. What is written here supercedes anything written previously. The modifications are, in my opinion, minor and fair.
Learning Paths and Rituals
This is a process to test even the most dilligent and dedicated Necromancer or Thaumaturge, and is not something that should be taken lightly. In order to even attempt such a feat, a source of information must be identified and located. There are two distinct methods by which this can be acieved:
1) Finding an Appropriate Teacher
The character rolls Manipulation+Mentor at a difficulty varying on what they hope to achieve. For a New Path, the difficulty is 7. For a new ritual, the difficulty is 3+Ritual Level. In order to attempt this, the Mentor must be available and in the location.
Learning via a Mentor is the preferred option. Both parties, Mentor and Student, make extended Intelligence+Occult rolls, until a total of 10 successes are achieved by the student at a difficulty of 7 for a New Path, or 3+Ritual Level for a ritual.
2) Self Teaching from a Tome or Scroll
The character rolls Intelligence+Academics to find the necessary tome or scroll in a properly prepared Occult Library, such as exists in a Chantry, at a difficulty of 7 for a New Path, or 3+Ritual Level for a ritual.
Upon locating a suitable tome or scroll, the character begins an extended Intelligence+Occult roll, until a total of 15 successes are achieved at a difficulty of 7 for a New Path, or 3+Ritual Level for a ritual.
Once the required number of successes have been achieved in either case, an amount of experience (7 for a New Path, or 1 per Level of a Ritual e.g. 2XP for a Level 2 Ritual) must be spent. This represents you character attuning the path/ritual to the power locked in their blood.
As per standard rulings, any 1's achieved will subtract from the number of successes already accumulated. If a botch is scored, all successes are lost, and there is a chance of a Necromantic or Thaumaturgical Backlash.
Backlash
Necromancers and Thaumaturges both dabble with dangerous forces and, despite careful planning and attention, sometimes things go wrong. These forces are dangerous, and unpredictable and anyone who attempts such an action, and achieves a botched result, will have something bad happen. This depends on the activity being attempted, and the severity of the botch, but will be decided by the Storyteller if/when it becomes an issue.