Imagine a bar of energy, similar to that seen under the "HP" bar in almost any RPG. In the MMORPG, the standard method of implementing this bar is just a 'pool' of points that has a regeneration rate. Abilities cost points, and more powerful abilities cost more points. It is easy to balance, and requires some strategy of which skills to use. Now the following concept has probably been implemented before, but I have never seen it myself. A bar of energy, that changes regeneration rates according to how much is left. The deeper you delve into the pool, the harder it is to gain it back. 100% energy - regeneration rate * 1.0 90% energy - regen * 1.0 80% energy - regen * 1.0 70% energy - regen * .95 60% energy - regen * .90 50% energy - regen * .80 40% energy - regen * .65 30% energy - regen * .45 20% energy - regen * .25 10% energy - regen * .10 0% energy - regen * .10 The trick is, you can 'focus' most abilities to do more damage/effect by channeling more energy into them. Channel too much, and you will unleash a very powerful attack, but you will be useless for a few moments afterwards. The regeneration rate would be much higher than in the standard MMO, such that to get from 0-100% energy should take only 90 seconds or so, even with the reduced regen rates. It's sort of an alternative for the 'cooldown' mechanic. As long as you stay within the 75-100% energy range, you can execute smaller attacks for as long as you like. But throw in a big one, that takes you down to 40% energy, and you have to be careful what your next move is. Channeling more energy is a linear cost, but your pool is no longer being used linearly. A small attack used when your are at 20% could really set you back, while a small attack used at 100% will have almost no effect on you. So, might this be a viable alternative? Personally I think it makes things more strategic than simply waiting for your ability to come off of cooldown. It might introduce more skill into fights than simply random dice rolls made by the computer.

That's an interesting implementation. Also good to know that it has been done successfuly before.

I guess what I'm even more curious about is the ability to increase the power and effect of your 'spells' and ablilities by using more energy than normal.

I know that Age of Conan did 'spellweaving', but from what I hear this feature is a death sentence if you are ever foolish enough to try it.

The EvE system was nice, because it gave your reserves a "breaking point". If you were stable at 70%, you had nothing to fear. Even at 40%, your recharge rate is high and you can sustain that pace indefinitely. But when your shields hit 30%, you knew you wouldn't be able to hold out, and it was time to use the energy and time you had left to try something new. Likewise, when your capacitor dropped past that point of no return, you'd have to start thinking about what you could turn off to save juice. Armor hardeners? Shield transfers? Guns?

But from your second post, it looks like you're looking for a cost/benefit equation dealing with the power of a spell and the time it takes to recover from it. You use 5% of your energy on a fireball, it singes the enemy's eyebrows and you're back to full mana before the smoke clears. Use 50%, it'll mess him up good, but you won't be able to do that again for a while. Put all your might into one shot, and you'll reduce the immediate area to a pane of blackened glass, but then it's nap time.

The idea has merit, to be sure. The idea that even the simplest tasks would exhaust you after a huge exertion is a good one. I've never seen anything quite like what you describe. I can imagine it happening two ways, one of which works, and one of which doesn't.

If it's a toe-to-toe standoff fighting system, like in Final Fantasy, the I don't think it'll work. Medium sizes will never be used. Players will use two sizes of spell: They'll have one that's sustainable spammable, channeling their recharge rate into effect at the most efficient rate, and they'll have one that burns the whole pool to nuke the crap out of the target, for use when the sustainable "bleed" isn't doing the job. Mathematically, there's no reason to ever use a 40% spell, since it'll diminish in value each time it's cast, and will also bruise your ability to do anything else. So if you're going to "break yourself" by exceeding the 20% "green zone", there's no reason to do it over the course of three or four spells, giving the bad guy a chance to heal or counterattack. In this context, a set of "basic" moves, analogous to the sustainable spam, and a set of "special moves", with penalty or cooldowns, analogous to the big bombs, would be a more elegant way of achieving the same end.

The other way I see it is in more of an open arena, treating your mana reservoir like the shields in Halo. You use some, then you stop using it and do something else. Maybe you hide, maybe you use an item, maybe you deliver a melee attack. Here, you aren't just tending your mana pool and converting it as efficiently as possible into effects, but are dipping into it as needed to dish out moves, and when it's gone, you aren't incapacitated, you just don't have that toolset available for a little while.

It's a good system I wish was used more in order to promote more strategy. I suggest that along with this system though, you wouldn't have the conventional "Spell takes this much mp, if you don't have it you can't cast" but instead spells take a percentage of your mp or stamina and depending on how much you have the more range, damage, area or accuracy you get. :P This is a part of an rpg system I'm designing.