Your 'sphere of influence' idea is interesting but sounds like it would add a lot of complexity for too little gain.

As far as mana per turn goes I don't see why it wouldn't be in the game.  I see spells with only mana costs to be 'burst' type spells of no great power (Single combat attacks or weak area effect spells).  Spells adding a small essence cost would be greatly enchanced 'burst' spells or something with a permenent effect.  Spells adding a large essence cost would imbue the target with a level of permenent spell effect making it part of the creatures makup.  Casting flight on a unit would allow it to fly as long as you paid the mana upkeep.  Casting 'Imbue Flight' would cause the unit to grow wings.

Sammual

Essense is a super limited resource.  It would mean you could only have x essense worth of perminant spells per turn.  That would effectivly be the same as the amount of mana per turn upkeep you could handle.  In fact, it may be a more balanced limit, because it wouldn't allow for stockpiling of mana, then blowing it all at once one upkeep-spells to steam roll the opponent.  

The 4 spells we have so far don't mention upkeep.   Though I guess they arn't persistant.  However the description of "creates something" makes it sound like its still an accurate guess.   Flaming swords, for example, was a mana-per-turn spell in MoM.   But it sounds like that would just cost essense in this game.

The spheres of influence of course are based on AoW.   I was just proposing ideas to how they'd work since they've been mentioned before.

I do not think that isn't the point of the thread.  I believe that is perfectly within terms of the discussion.  Its still a 'limit' of sorts.  starting cast

Actually, I'd likely vote against the sphere of influence if I was given a vote, at least in terms of 'can't cast the spell past this point'.   I would not, however, feel it is unreasable to have "within influence" and "out of influence" changes.  Say, you can cast spells globally, but outside influence (or into different dimensions) you have a higher casting cost, or different casting rules apply.   In MoM, it was a global casting with a minor "distance from tower" effect that gave no way to sense the scale.  I'd deem it reasonable to keep the idea of a sphere of influence, as given by AoW, but change it to be less limiting.  Perhaps sphere's of influence radiate from all converted land (its about reviving the world, right?), so land you control has better magical control than land you don't control.  

some kind of range modifier is likely a nessessity so you can't fire bolts at maximum power at enemy capitals the same way you can use them to defend your own land, at least not until late game.   Only until borders start pressing each other should magic range really start being able to heavily influence enemy territory without higher cost.

Oh, I forgot to mention.  We have psudo-confirmation on what appears to be sphere of influence.  Look at the screenshots

https://www.elementalgame.com/Screenshots/Empire_Fire_Shard_1280.jpg

Click the link for the official example

you can see in the mini-map at the bottom, there are obvious color rings to show some sort of limit.  It also looks like there are multiple sources (since its not just a singe circle).  

Well, I call it "pseudo" because it isn't a real confirmation.  If we knew what it was, I would not have through "pseudo" on there.  

if its from culture, I'd argue that culture doesn't spread in such clean circles.   I'd be curious to see how borders worked like that.

it makes sense in GC2.  I imagine those rings represent radio waves or something similar extending out from their sources (the ships obviously travering faster than the speed of light) so everything within those areas capable of recieving culture (i.e. has mastered the radio or TV) will be influenced by that civ's culture.  It doesn't work like that one a single planet

Though you do have a point, it could just be other mechanics being built with the engine that might not be used (GalCiv3 is said to be using this engine when it gets put into production, yes?)

I love quibble.  It heartens my troll senses

Trade routes should totally extend your influences.  It always has.  Historians can tell who traded with whom entirly based on influences of culture.

If caravans travel between different nations, they should carry bits of influence with them.   It would encourage influence enhancing technologies, spells, and buildings.   I know it upsets some people, but I usually find the near-turning of one of my cities by influence to be a push to go to war,  Though perhaps there are more realistic results to influance other than alligance switching.

I personally don't think that complexity and micromanagement are directly related.  I've  seen some pretty simple systems that require micromanagement (mostly in real-time games) and some pretty complex systems that don't (pokemon for example, a surprising number of variables exist in the VG pkmn).  Stardock is trying to use adaptive AI to create anti-micro without harming complexity, and I commend them for that and hope we see good result.

I totally agree that trade routes should spread culture! That'd be awesome, and it would make winning via a culture/influence victory so much more engaging. In GC2 and Civ IV, for example, influence/culture victories were either much more boring than most others, or largely side effects of having already conquered much of the world. The reason being, as Swicord mentioned, that settlements (and in GC2 influence starbases) were the only sources of culture. If trade also spread it, you'd actually get to do something while trying to achieve one of those victories. You'd actively try to spread your trading arms far and wide, and could choose to focus heavily in one area or to spread out your trade routes...

So yeah... If there is going to be any influence/culture in Elemental, it should definitely be spread by trade!

Also I don't want to see the Civ IV effect of culturally invincible cities. Old cities with a handful of wonders under their belt in Civ IV were totally indomitable via culture. If you conquered a city close to a few of such enemy cities, the only way to prevent their culture from completely swamping it was to conquer those cities as well (unless your civ's culture was already so strong that it overpowers them). But to me, that feels so static, and it should be more dynamic.

This isn't really important at all but I'd like to point out that you have "EMoW" in the subtitle. But this game is not going to be called Elemental: Magic of War, although could be an interesting game, too.