For my game, I want EBWs to advance their Formulae skill as fast as possible. To do this, I needed to provide a carrot to get the players to chase other than Getting close & Necanthrope transformation. And from reading quite a few quotes in the MRB about EBWs loosing their mind, I want there to be a cost. So...
When calculating an ebb power, if the desired ability rank is less than the EBW skill with that ability, then success is automatic, unless a concentration roll is required due to conditions.
If the ability rank exceeds skill in the ability, then the EBW must make a roll of 11 + Ability Rank, adding Skill Rank and Formulae.
If the roll is failed and the ability rank does not exceed (skill + formulae) the EBW looses the flux. If the ability rank exceeds (skill + formulae), the EBW will loose the flux and take 1 HP of damage per point of Flux "burnt".
Examples:
An EBW with Blast at skill 6 and formulae 3 activates...
...a rank 4 ability. This automatically succeeds.
...a rank 7 ability. The EBW must roll a total of (11 + 7) 18 with a bonus of (6 + 3) 9 on the die. If the ability fails, the flux is lost.
...a rank 12 ability. The EBW must roll a total of (11 + 12) 23 with a bonus of (6 + 3) 9 on the die. If the ability fails, the flux is lost and HP damage equal to the flux lost is taken.Formulae is considered a concentration based skill. It still requires both the GMs permission and experience points to advance. Concentration rolls to activate an ability under stress can now be used as modifiers to the formulae skill.
Sanity
Formulae threatens sanity. For every point of Formulae ability, reduce the EBW's stress limit by 1. e.g. a character with Formulae 3 and a cool of 8, so a 16 stress limit, will find their stress limit reduced to ((cool x 2) - formulae) 13.To make necanthropes viable, either ignore the sanity rule, or alternatively, reduce stress limit by formula for skill levels 1 to 10, then reduce the penalty by 1 for skill 11 to 20. i.e. Formulae 9 = 9 stress loss, 10 = 10 stress loss, 11 = 9 stress loss, 12 = 8 stress loss, 13 = 7 stress loss, etc.