Semi-OT - FFXIV is a good example of doing it right. (Gaming)

by someotherguy, Hertfordshire, England, Thursday, June 23, 2016, 11:36 (3161 days ago) @ Kahzgul

The most obvious example is the Thaumaturge/Black Mage, who has two separate stances based on whether he's using Fire or Ice spells. The Fire stance increases mana cost and spell damage with every stack, which quickly leads to running out of Mana. The Ice stance deals less damage but rapidly restores mana, making it a dance of dealing as much damage as you can in fire stance, switching to Ice before running out of Mana then getting back to maximum Fire stacks as quickly as possible to maintain high damage.
Add in a number of CC or AoE attacks that will either swap stances instantly, or use all of your MP at once, plus procs that grant you free spell usage under the right circumstances and it becomes a pretty intricate dance that constantly rewards good play.

Dragoons also have a buff/resource that unlocks additional attacks when active. when used, those attacks increase the buff timer, but you can also spend some to deal additional bursts of damage. Again, it comes down to a balance of trying to use as much of the resource as possible for the extra damage, without letting it drop off completely.

Monks (which I main) have almost the reverse of the Mana situation, where you start from nothing and build up Greased Lightning, buffing your attack speed and damage in a feedback loop (a lot like berserker classes in other games). But the buff is on a short timer (13 seconds) and takes a minimum of ~7 seconds to top up, meaning you have to really keep on top of your fight awareness. If you're out of combat for just 6 seconds, you have to start over from nothing again.

I'm sure none of these are new concepts, and I don't know how many if any of you found that wall of text interesting, but purely from a game design standpoint I find these mechanics pretty fascinating - all the classes have their own limitations and failure states, but if you're good there's no reason why you should ever reach an "I've run out of Mana" situation.