In League of Legends, there are quite a few champions that don't use mana. I am wondering if there are any pages or posts that explain why Riot chooses to create a champion that doesn't use mana? What is their rationale behind the choice?
There are champions like Shen, Kennen, and Akali that use energy, which is kind of similar to mana in limiting the spamming of abilities (although you don't buy energy items like you do mana items).
There are also a few like Mundo, Vlad, and Morde where their abilities cost health - that kind of makes sense to me - at least there is a cost to using abilities.
But the champions that really puzzle me are the ones like Riven, Garen, and Katarina. It just doesn't make sense why they get to use their abilities for free, and never have to spend gold on mana related items.
Kha'Zix versus Rengar
And most recently - Why does Kha'Zix need mana, and Rengar doesn't? Is there a rhyme or reason behind Riot's decision to build mana into Kha' but not Rengar?
I'm just wondering if there any posts or releases from Riot that explain this, or maybe even a champion spotlight where they explain it?
Thanks to help from @Brian Colvin I was able to track down a few forum posts. I'm updating my post because someone locked it, but I still think the information is valuable, and I have no clue where else to ask the question but on stack exchange.
Morello answered a question in the forums that somewhat touches on this subject:
The reason is manaless champions need to be balanced specifically to not use any (besides health) attrition in their gameplay. Infuse is an example that removes attrition from characters designed to have it. For example, giving Kog'Maw infinite mana is much, much more broken than making Kog'Maw manaless and gating his ultimate in some other way.
Another person asked a question about manaless champions, and Morello answered with this:
...I do agree mana gives another balancing point to champions. You have to design manaless champions to have other attrition (melee does since it's more risky, health costs, more cooldown considerations, etc) but they can be made functional if you're smart about it. Vlad's definitely the antithesis of this paradigm though, as he gains resources over time.
I didn't find anything too concrete, but I do thank @Brian Colvin for taking the time to point me in the right direction. I'd give you upvotes if I could!