Re: About recovery and CP cost of ER (Magical)
 

If the disadvantage will never be applied because of setting switches it is not a disadvange and gains you no points.

Re: About recovery and CP cost of ER (Magical)
 

Magical, -10% could be applied though if the character can't recover the ER in no mana areas.

Re: About recovery and CP cost of ER (Magical)
 

This would also imply that your Energy Reserve was vulnerable to magical countermeasures. So someone could cast Dispel Magic on you, and eliminate your ER. I'd probably rule in those cases that the ER vanishes for the duration of the cancelling ability or spell, and when the duration ended, your ER would be empty and you'd have to refill it normally.

Re: About recovery and CP cost of ER (Magical)
 

Be very careful sticking power modifiers on Energy Reserve. In general, you shouldn't. Almost all modifiers permitted on ER concern one of two things: (1) what the ER can be used for (e.g., just one power of a given source, just abilities, or just extra efforts and stunts), or (2) conditions on recharge (slowly, only under special circumstances, etc.).

Something like ER (Magical) or (Psionic) is already limited to powering magic or psionics, so you can't get a discount for it only working with magic or psionics. The reason why you pay 3 points/level for ER just as you do for FP is that while FP works with anything and thus is more broadly useful, ER can't be drained, has no bad effects on your health when low, and recharges no matter what you do. Those benefits are considered sufficient to balance the drawback of being limited to one power source.

There are older GURPS books that suggest things like Fatigue Points bought with limitations like "Magic only, -20%" or "Psionics only, -20%." That's fine . . . it amounts to buying an ER that can be drained, recharges only when FP would drain, and so on. It isn't a vey good deal, really, but it's legitimate.

However, those limitations ("Magic only," "Psionics only," etc.) aren't valid for Energy Reserve, which already has such a limitation built in. They're also not power modifiers.

Re: About recovery and CP cost of ER (Magical)
 

Does counteracting that -20% from older books mean that the combined benefits of "doesn't need rest to recover" and "doesn't cause penalties when low" is worth +20%?

Re: About recovery and CP cost of ER (Magical)
 

It's actually three benefits, not two, and one drawback:

1. Good: Doesn't increase the threshold (1/3fp) for being 'very tired'.
2. Good: separate recovery (it recovers in addition to normal fp)
3. Good: automatic recovery (it recovers regardless of actions taken)
4. Bad: doesn't increase the threshold (-1xFP) for automatic unconsciousness.

Re: About recovery and CP cost of ER (Magical)
 

Perhaps another approach might be to define basic FP's 3 points in terms of those benefits (like threshold for automatic unconsciousness) and defined its regeneration as a "requires rest" form of Regeneration, ignoring the usual guidelines of not being able to buy low-level versions of Regeneration for FP Only.

Re: About recovery and CP cost of ER (Magical)
 

The main problem with low level versions of regeneration for FP is that they're useless; 25 points for +1 fp/hour is not impressive.

Re: About recovery and CP cost of ER (Magical)
 

Especially considering that you could purchase ER 6 for 18 CP, which recharges 1 ER/10 minutes, so you get six times the benefit of that level of FP regeneration for less cost.