Dependency (Fear) is a Dependency listed for the Ripper on H70.
In their case a weekly "dose" of it is needed to avoid HP loss.
It isn't entirely clear how to quantify "gaining" that does.
They do not have Terror to induce a Fright Check, nor even a Racial Talent for Intimidation, which can occasionally induce them. They would be capable of using it at default, but due to a lack of IQ or Will bonus would not be very good at it (only RESISTING it) innately, meaning they would need to rely on shows of force to get bonuses to the roll.
"Variations" do mention using Terror as a shortcut, and of using Metuovore on Leech, and H71's Spectral Ripper specifically uses Obligate Metuovore limitation (instead of fear giving bonus HP stole, fear sets base HP stole)
- interestingly, the SR limits the Invisibility gained from stacking the Specter trait with only while unobserved, which would normally apply to being unable to switch it on, but could also apply if someone had See Invisible and spotted them while it was on: that should cancel it and make them visible to EVERYONE until EVERYONE stops observing them
Leech is a means of recovering HP (default this is 1 HP per 3 HP stolen without Increased Healing enhancement) but H21 basically gives a mechanic for how Fright Checks translate into HP: it's the margin of failure.
If using "1 HP is dose" approach for Succubus or similar, then when there is no actual Leech ability, using a similar formula for Terror could make sense. The only difference being that Terror would not restore HP first before feeding, and that Terror doesn't actually steal and HP or FP.
- That could be seen as unbalanced: if nothing is quantifiably stolen then there's no limiting factor for sustainability of a food source
- for example, should a Ripper really just, if someone fails a Fright Check by 1 and rolls a 3/4 (just stunned for merely 1 second) should that be all it takes to fill a Ripper's needs for a week.
For that reason... don't just let ANY old failed fright check work. Only CERTAIN results. For example on B361:
- results 14/15 result in a loss of FP: that could count as a dose
- causing permanent losses in points should also count
- result 31 seizure which drains FP
- injury caused by heart attack or stroke
This advanced requirement (beyond Leech) makes the Ripper far more insidious: they would need to torture a target a LONG time to get a proper result to fill their needs.
If the above is TOO rigid (while "MoF" is too generous) instead of a "dose" being based on the margin of the fail, it could be based on the quantity of the result. Like: due to lacking "Leech" to efficiently extract fear as energy (using that and "wasting healing" to do a "Dependency Dose" should be rewarding: Leech is EXPENSIVE) instead of "MoF1=dose" the MoF+3d roll(s) should need to reach a certain quantity for a dose.
So for example if it was 10 as a dose, 1 failed check by MoF 1 and rolling 9 would fulfill a dose in a single failed Fright Check, but it might take as many as 3 (the minimum possible to get on the table is 4, x3=12)
For "Dependency" it also makes sense to assign a "Dependency Dose Vitality Reserve" equal to "damage intervals per dose period" (eg you need DDVR 24 if you take 1 HP per hour per missed daily dose) and treat the "dose quantity" building it up to 24, while it depletes at a fixed 1/hour.
This means "a day in advance" is the most you can get (necessitating daily doses) while giving a more continuous incrementing system.