My 2 cents - separate the gameplay aspect from the realism aspect, and let the game-play drive the decision. It's a fantasy fictional game and those are written in reverse order of importance.

Game-play wise, defenders need to be able to develop and express classic defensive advantages - interior lines of communication/supply/movement, the ability to prepare and improve terrain for defensive bonuses, and to be able to create and man choke points.

Attackers need to be able to capitalize on the fact that a defender can't be strong everywhere, leverage terrain of their own (if the defender fails to do so or can be drawn out of position), and (going back to #1) have *opportunities* (not guarantees) to be able to bypass choke-points (either by good maneuver or potentially tactical mobility advantages - e.g. horses or magic).

I'm somewhat less concerned as to whether this implies a specific 'zone of control' feature beyond a single 'tile'. It can be addressed with how maps are created (particularly with respect to 'impassable' or restricted-movement terrain), and other map features that factor into tactical combat (I've seen it mentioned elsewhere that controlling the high ground will be factored into combat; add in things like swamps, forests, and the like). If you can identify choke points - and/or potentially create ones where it's reasonable, you've pretty much got what you need for interesting game play (e.g. maybe you can expand a single-'square' fort to 'control' adjacent squares, but you can't *practically* wall off a miles-wide plain (late game magic is always another story - destroying such a wall is also).

Giving some units the ability to 'intercept' is another good way to present a feature LIKE zone-of-control but restrict it to types that make sense; e.g. perhaps an outpost gives all units +1 to visibility range, and also units with 'intercept' (most flying units, light-to-medium cavalry, non-capital warships, etc.) +1 to their intercept range, but it won't confer intercept on units that don't already have it. I like giving the defender the choice to actually intercept or not, though that may be tricky to do since the strategy level is turn-based. If it could be done, I'd like that.

In the end, I think map design is going to do a lot to either demonstrate the need for something like a ZOC attribute, OR to prove that this game won't need anything so mechanical.

Chris

Just make it simple.From war games ZoC and overruns behave like this:

When a unit enters a Zone of Control it must stop movement, even if it has remaining movement points. Except to attack the enemy unit. So any unit exerts a ZoC, units in forts just make it less interesting to attack it.

Overrun,  when you enter a ZOC and kill the enemy unit, wining by X%. You have completely demolished the enemy and can keep moving. Otherwise movement is done.

allowing an army to hide in ambush (this would be cool)

allowing a hidden screen that purposely lets the army pass, and then attacks from the rear when battle with a second force commences (this would be cool)

allowing for a small defensive (scouting force) to retreat (would be nice)

allowing for a well equipped/well prepared defensive force to exert a Zone of Control ... whereby all potential attackers passing through the area would be forced to face the defending army in a tactical battle (with "supply" bonuses) if the defending army, after seeing the attacking army, so chooses to engage them in combat. (that would be cool)

Having stealth armies that can move around on the map relatively hidden, invisible to the opposition and immune to ZOC (this would be cool)

I like the "intercept" idea a little more than the ZOC.  Either might be better than nothing.Agree with Zentax that "I think map design is going to do a lot to either demonstrate the need for something like a ZOC attribute, OR to prove that this game won't need anything so mechanical".

Ambushes sound nice, but I was disappointed by they way they worked in Rome:TW.  If they can't implement them better somehow, don't do them at all.

You don't even need an "auto engage" system, merely there is a pop-up (for the defender) every time an army comes into range of your ZOC army. (on the attacker's turn). The attacker's move pauses when his unit comes into range of the ZOC, thats when pop-up happens, and you make a choice. Then either battle happens, or you decide NOT to fight, and then the attacker's turn continues.

If you DO fight, afterwards you are auto-placed back into your ZOC position, wether it be "fort", "camp", or just an empty tile.

While I agree that realism is a good thing, why should we strive for "simplicity" and shun complexity?  Complexity is a good thing, IMO.  This is a strategy game, not candyland!  Complexity often leads to diverse and unique strategies, and endless possibilities.  Look at Dwarf Fortress: even though its still an unfinished alpha, people have done some incredibly awesome things with its extremely complex systems, it's been all that I've been playing while waiting for Beta 2.

For example: Mermaid farming.    Because of the obscene valus of mermaid bones in the game, one player captured and bred mermaids for their bones.  If the game had been simplified and abstracted, this, and many other projects would not have been possible.

In fact, the combat system in that game is amazing: it even tracks organs, bones, and even teeth:  if one of your dwarfs loses an arm, it's gone forever, a leg, they'll need a crutch, making you think twice before you put a powerful hero into a dangerous situation, he might never recover fully.  With HP systems, you can go down to 1 HP, and be fresh as a daisy, after some recovery time.

And so, I see no reason complexity should be shunned, it may take longer to learn the game, but after you do, it shall be far more rewarding.

I'm not saying we should make Elemental as complex as Dwarf Fortress, that would be incredibly difficult and time-consuming, but we should embrace complexity with open arms.

Though if it weren't an almost unattainable goal, I'd say make it at least as complex as Dwarf Fortress.    Though I'd probably be the only person to ever play it. . .

OK, I'll try to continue the discussion about simplicity and complexity that started in another thread.

I guess your "club" will have to make its own mod, which complicates things as much as possible  The normal game is going to be quite simple, which is good for me. I prefer diversity over complexity - the basic rules should be simple, but there should be many things to "explore" in the game - units (or unit components), spells, NPCs, items and so on, with their own special abilities. A good example is the "Magic: the Gathering" card game, I think it's not a coincidence that the information cards in Elemental look much like the MtG cards.

Some ideas posted at this forum are really too complicated to be worth implementing. Remember that Stardock is a company which purpose it to make money, so they won't implement anything that probably won't be interesting for a wider audience. I have nothing against realism, but it shouldn't be the only reason to add a new feature to the game - it should be also fun. And I think that if you need to write a "wall of text" to explain your idea, it's probably not worth adding to the game 

Another thing is the AI - adding a new feature might seem easy to do, but the hardest part is to "teach" the AI to use it, which can take much more "engineering hours" (as Frogboy says) than implementing the feature itself.