The Last Gasp, Powers, Costs FP and Energy Reserve

[Mailanka]

In my samurai campaign, I used both the Last Gasp and Energy Reserves, and I allowed the latter to act as points for Extra Effort (since it represented Chi) which is beyond what you intend to do in your campaign. I did not charge extra for it. It worked out fine.

It turns out ER isn't priced "against fatigue," it's priced against spending it on powers and such, which is its purpose. Remember, the original role of fatigue is not just enduring hikes and such, but also powering spells. Since you want energy reserves powering spells, this seems perfect. In my game, Chi reserves were used to power Chi abilities, and it was much sought after... but not as much as you might think. I had a few perk prerequisites that made it a little tricky (but not too hard) to get and limited how much you could have, but again, I gave it more benefits than you did.

Hit points also take a very long time to recover, but they're actually cheaper than fatigue points. In the original magic system, you could spend fatigue (which recovered quickly) or you could spend HP (which took forever to recover). When you use the Last Gasp and Energy Reserves, you get a similar story: You could spend from your energy reserves, which recover quickly, or you could spend from your fatigue, which took forever to recover and penalized you. In effect, ER becomes like Action Points in Last Gasp, or like Fatigue in the Fatigue/HP dichotomy of vanilla magic.

So I wouldn't worry about it. Toss on a special recovery condition if you're really worried, but in practice, I think you'll find that it's not too much of a problem.