Balancing Regen

[Humble_Bee]

I'm trying to make all my stats balanced, and this is pretty easy with ideas like accuracy, damage, and damage resist, but I'm having a hell of a time with regen. While accuracy, damage, and damage resistance all interact with each other, regen does not nicely interact with them. If 1 SP allows you to do 10 damage, and you start with 120 SP, then you could do 1200 damage before you run out. If each attack takes 1 sec to cast, it would take you 120 secs to run out of SP, and then you would have to wait to until you regenerated your SP. If you regen 3% Base SP per 6 seconds (not adding bonus Max SP values in), it would take you 240 seconds to get to full. Now, if I put this into total damage output over time, this base would look like this:

At 2 minutes (No Stat Boosts):

60 SP Leftover

1200 damage done

At 16 minutes (No Stat Boosts):

0 SP leftover

6000 damage done

And then if you compare a double regen boost vs a double Max SP boost, it would look like this:

At 2 minutes (Regen Doubled):

120 SP leftover

1200 damage done

At 16 minutes (Regen Doubled):

120 SP leftover

9600 damage done

--

At 2 minutes (Max SP Doubled):

120 SP leftover

1200 damage done

At 16 minutes (Max SP Doubled):

0 SP leftover

7200 damage done

As you can see, in the long run, depending on how you set base regen, when you double it, it doesn't tend to balance out. This is even more problematic for HP regen, because if you double 3% HP per 6 seconds, it becomes 1% HP per second, which usually is more than most people think is balanced. On top of this, we come into the problem of potions. If a game is using potions or Inns, a person then has to calculate the value of regen vs how cheap potions are or how time consuming it is to get to an inn. If potions are cheap, regen loses value. If it's easy to travel and get back to an inn, regen also loses value. It can be a really tough concept to balance with stat boosts. Any ideas on how you all would balance it?