I agree, I think this system would work perfectly with a class that has more of a distinction between their different skills. It could be like focus and adrenaline. These two aspects are very different. Focus could be used for ranged attacks with a bow and adrenaline for when they charge into the fight.
It won't necesarily be lower dmg. Like they said wih the monk, I played to his fullest potential he will have the highest dmg output but newbs can still play as the monk and do comparable dmg. It just gives advanced players an opportunity to maximize dmg output
I understand. I think a limitless system just doesn't work. Even the wizard went to a pool. If the barb runs out of enemies then he is out, not to mention starting at zero. I also don't think that the cost and gain have to differ to greatly for most spells. It would mainly be for skills such as Blizzard, that we do not want people being able to cast over and over again. The two sides would balance out for the most part but eventually both sides would be exhausted. I don't think it is as complicated as you may think it is. You are not constantly going to be thinking about balancing out both sides. It just allows an opportunity for player skill to make your character stronger.
It is a system that allows new players to use it easily but has potential for skilled players to maximize their damage output. It has nothing to do with calculations but understanding skill choices and combinations to maximize potential. Separate sources would completely ruin the dynamic of this system and what makes it so different from the others.
The Barb has infinite energy as long as he keeps dealing damage.
Does this thing regenerate over time or something? I also don't see the great strategic aspect. You spam skill 1 until you run out of one resource, then you spam the skill 2, then 1, then 2, and on and on. So instead of smashing one button you will be smashing two. The only thing this does is to force this dual skill behavior, it doesn't really spice up gameplay.
One, this resource can go for a long time without running out if you use the right spells. You won't necessarily be able to spam two skills because certain skills will not gain one as much as it uses the other. It will not always be a 50/50 situation like one side is 25 so the other has to be 75. You could have 20 on one side and 15 on the other. Weaker spells will be a more equal gain/loss so you can spam these more frequently but stronger spells may cost a significant loss with only minimal gain. If one side is low, and you use this, you won't gain much back so you will have to only use weak spell to gain it back up. It spices up gameplay by driving your characters skill selections to keep the balance. And as I said, they will both slowly regen out of combat. So you will start off strong and it will be up to you to keep you energy source abundant. There will more likely be more of loss per skill than gain to make sure you can't constantly spam more skills.
So far, we know how four of the five energy systems work. The Barbarian's is a pool that starts at zero and is gained through fighting. The Monk has a two part system with combo points building to create energy for other moves. The Witch Doctor has the classic mana and the Wizard has a set pool that drains as she cast spells.
I think that the last class will have a energy system that relies on balance. I originally had this idea for the Wizard's instability but with that gone, I think they could apply it to the last class. Overall, how it works is that half of your skills drain one side but raise the other. The other half raises the opposite side and drains the other.
For example (disregard names and skills, this is just to illustrate how the system works and not what the last class will have):
Mulit-shot: -15 concentration +15 nature
You loose concentration since it is needed to shoot the arrow but you gain nature from not using it.
Venom: +10 concentration -10 nature
You loose nature since you need it for the spell but regain concentration because it was not needed for venom.
Now, to make sure that you do not have an unlimited supply of energy which none of the other classes have, there will be an imbalance to some of the subtraction and gain like you +15 concentration and - 20 nature for one spell and -30 concentration +5 nature for another.
What this system allows is for a wide use of differing skills but you cannot constantly spam one skill over and over. But does allow for continual use of different skills. Strategy is also needed for this system to maximize the amount of spells you can cast without running out of energy. Blizzard has said that they want these different systems to help drive how you play your character and this does just that. It is also fairly simple, which is also important so players don't have to think too much about their energy system. When out of combat both your concentration and nature will regain since you are not using either.
This system can also be applied to a number of different situations the last class may have. If it is a bow user, the other side can add a bit of magic for him to use. If he has a pet then one side can be for his attacks and the other for the pet's. If it is for some sort of knight class/tank class, one can be for defense and the other offense. The point is, the simple mechanic can be applied to several different situations and still be viable.