"C" seems like the most sensible solution.

I'd like to chime in with Scoutdog for option A with a strong tie-in to the economics and diplomacy model.  Option A opens up so many interesting economic, strategic and espionage options.

If you don't have the resource, you can't build the unit.  "But, but, but I really want my gray dragonscale mail-wearing rangers sneaking around in their extra-comfy frogskin moccasins!"  Fine, here are the ways you can get it:

• Go to war and take the swamps where the extra-comfy frogs live back from the blue player.
• Buy extra-comfy frogskins from the blue player.  If you completed the transaction, a caravan would leave the appropriate city for your empire.  Better make sure it doesn't get attacked along the way; those extra-comfy frogskins are a valuable commodity.
  
• Have your spies find out which city has the warehouse storing the extra-comfy frogskins and steal them for you.
• Have your spies find out which caravans are carrying extra-comfy frogskins to someone else and raid them.

A simpler alternative would be option A with a automatic trading system.  If you don't have what you need for your unit, a dialog pops up telling you what you're lacking and how much it will cost you to procure it.  Players would need a resource page where they could flag what they need and which items they're willing to sell.  I'm sure this would be a bit of an AI challenge for single-player games to have the AI trade intelligently.

Although I think the number of different resources should be large, I think the actual quantities of most of those resources should be rare.  I'd like to play in a world where scarcity forces us to be creative with unit design so everyone's units end up different every game.

A, B & C are all un-cool.  In my own programming projects (you get one guess which language) choices like that mean it is time to re-visit the things I thought I had decided.

For starters, separate the potions, magic leaves, etc, from the design process and let any unit or hero who carries them get the benifit (surely you weren't going to have potions for ordinary units and not for heroes, were you?).  Having fewer required ingredients means that the A/B/C choice won't happen quite so often.

Then as Elkoba said, "Option C, but keep the "bonus equipment" as part of the unit, just greyed out on the units profile.  If/when your empire re-aquires the resource, you can move your unit back to a city, and hit "re-supply" or something to bring that unit up to standard", seems like a good starting point, although, as others have said, the lack should be indicated clearly.  It might be nice not to have to move the unit to a city to add the missing items, but I'm so used to that from other games that it wouldn't really bother me.

Or maybe we could have some sort of blacksmith capability (has to be separately researched) to permit units to upgrade in the field?

---------------------------------------------

Regarding the units stats:  I hope  attack / defence / speed & hit-points wasn't intended to be a complete list.  Ideally there would also be magic-resistance, endurance, & mobility.  "Attack" could include chance-to-hit and damage-if-it-hits.  Defence could be separated into armor (protects against everything non-magic), shield (protects only in front) and defence-skill (effective in melee, but won't stop arrows).  Pardon me if my Total-War & MOM are showing

---------------------------------------------

Regarding special abilities like "first strike", those could come automagicially from special weapons.  Axe & halberd get armor-piercing, cav with long lances get first-strike, inf with long pikes get negate-first-strike, etc.  I'd really like to see these in the game.

------------------------------------

Meanwhile, I like the idea of lots of extra metals like mithril, adamantium, etc, but I worry about possibly making them un-usable if the resources are hard to find AND we need some special skill that takes a long time to research, or a special smithy that takes a long time to build.  Maybe mithril should be medium-easy to research one you have the pre-requisites, like iron/steel skill and some mithril in hand to experiment with.

Well... While I am an idiot and apparently missed this thing going into beta so I don't know completely what you are talking about... here is my take.

If you don't have the supplies... the unit should not get built.

Reasons why other methods have flaws.

1.) Anything else trivializes the resource to some degree.... if various kinds of resources are availible like mithril and adamantium for instance you will have to make a choice... guard the best?  guard the easiest to defend due to proximity? guard them both but with less forces than guarding 1 to make it harder for your enemies to get good gear?

2.) If it's time/money to compensate... odds are someone will figure out how to reduce the time or make gigantic amounts of money in an easier to defend style.

3.) If you can stock pile resources in warehouses if the resource keeps swapping hands you won't be able to tell 1 team from the other team... everyone will have the good stuff.

4.) If you allow the unit to be built but with lower quality weapons etc... it's NOT that unit... so what is it?  If you have for instance a Paladin and you have him equipped with a horse, plate mail, and some sort of healing item.. and you lose the healing item... he is not a paladin... he is a knight.  But knights don't exist... so you have this paladin that is named paladin but IS NOT A PALADIN.  How do you plan on tracking 3-4 varients of the same unit?  I tell you how... you flat out don't let it happen.  This makes life easier for not only the game engine... but for the players as well.

Other side note :

Masters of Magic only let you equip heros.... you have less heros therefore it's easier to keep track.  Not every game needs to get more complex with the next generation... the simplicity of chess, tetris, and other suck games is sometimes the beauty of it.  In masters of magic if I wanted a ranged troop I picked archer or magician... and it was basically pre-built... the beauty of the game wasn't in the units... it was in the stacks of units you put together.

Here is a thought... go back to pre-made "classes" of units... add heros to the game if they aren't there now and limit the number of them you can have... let them use equipment.  If you really want to make the units special by themselves add a new "class" called "caravan" or something like that.  The caravan can go to the mithril mine... and grab x amounts of units... if that caravan meets up with your group of "dreadknights" they get a "magical enhancement" that is "mithril armor +5 defense" or something like that... and it's inventory is reduced.

Caravan Rules :
1.) Can not be protected in a city
2.) Can not be "stacked" with other caravans (to avoid "uber caravans" that are so well protected they are immune to attack and have the ability to basically haul half the planet with them per trip)
3.) If a caravan is destroyed the amount of that resource is left laying in that location... IF another caravan comes upon it... they can pick it up.
4.) If a caravan holds a resource for too long... it vanishes with a message of "caravan sold it's goods on the black market and retired"
5.) You should be able to assign a caravan a route, how often it repeats it, and how it reacts to enemy units as they get close (run back to city, run back to closest city or resource, hold it's ground using stacked units, run away randomly, destroy goods) this is when they get within visible range.  Obviously destroying the goods holds a lock on the resource but can seriously cripple your own stock pile as well since an attack is not needed to force the destruction... merely the threat of possible attack.

This gives you a minor stockpile... makes you manage "trade routes" basically to the resource and back.. and makes it difficult to protect.  Realistically when I was playing Civ 4 and I had oil in like Africa... and I started making tanks in America a second latter... that's kind of silly... the best place for me to logically make tanks if I needed oil was in Africa... but since the product was assumed safe during transport it didn't make me protect anything but the oil... if the game was realistic I should have had refineries, facories, etc... all over that general area in africa where the mine was... and THAT is where all my tanks should have been made to avoid my enemy stealing my oil while in transit.  This would have had me protecting a much larger area in Africa and ramping up my assets in that area.

The Caravan unit and transporting of resources perhaps needs a little tweaking because I came up with it in say 10 mins of thought... but you can see what I am going for... a more realistic management of resources... a slight delay on impact from losing the resource... and owning just the resource points doesn't mean you have a 100% monopoly on that resource if they are killing your caravans and stealing your supplies.

I know it's a bit late for radical changes... so this is probably falling on deaf ears or being filed under "for the sequel" but in my defense... no one asked my opinion prior

"Here is a thought... go back to pre-made "classes" of units"

I wish they would, but I think the devs have gone so far in the other direction it's a lost cause.  Probably they are shaped by their Galactic Civilizations heritage.  Space games often have unit(ship) design features, and probably need them.  MOM, Elemental, etc, don't because they have enough going on with spells, heroes, etc.

I like that but have it so that players have their stockpiles for sale on an open market and that's the only way it happens, unless the real bandits are selling e.g. bandits raid my Iron caravan, and sell my iron to you. Or I've got my excess iron on the market and if I'm not at war with you or trade embargoing you, you can buy at the price I've set. Computer players buy and sell as it suits them.

Given that - each person in Elemental is an individual, I’m more for a skill based unit design, you should be able to recruit a peasant, a raw recruit, and train that person to a role.  Warrior – Scout – Caster – Healer etc.  and have a grade 1 recruit.

The roles should have different levels of training and as they advance cost more to train and have greater ability to use equipment at higher levels. Warrior becomes a Guard – Guard becomes a Knight - or whatever labels you want to use.

You recruit a Warrior and have a choice – use him as a grade one combat type or send him back to the barracks and train him into a Guard (grade two combat type.)

A Warrior might be able to use leather armour while a Guard might be able to use leather armour and chain armour – while a Knight would be able to use Leather, chain and Plate. 

But you could not train a Guard until you had the technological advance Veteran Units – or a Knight – until you had the Expert Units advance.

A Guard would have a higher attack, defence, and health than a Warrior. A grade 2 Mage would have would also have higher casting skill or magical power than a grade 1 Caster. A grade 2 Ranger would have greater stalk and hide and wider perception than a mere Scout. Etc.

Units should be able to gain experience and progress up higher levels by being played and surviving combat in the case of warrior or maybe time spent undetected in enemy territory for a scout.

When it comes to equipment, everything you make or harvest should be stored.  You  could trade the Mithril ore or send it to a blacksmith to make armour and weapons. You could then trade the armour and weapons or use them to equip Units.

Creating units should depend on what you have in stock - if you train a Knight and then make a Mithril Helmet, a Mithril Plate Mail, a Leather Boots and a Mithril sword then you equip them on the Knight and call him/her and Dread Knight.  That then becomes a template.  But you can’t create more of the template unless you have the equipment in stock and an available recruit of the proper type and level.  If you don’t then you can’t make the unit.   So Choice A.  But -

When it comes to micro management getting boring I’d suggest that “simple equipment” and “simple recruits” always be deemed to be available – you always have   - As examples  - Iron, Leather and wood and grade 1 recruits. Etc…

You can always make Leather - Iron and wooden armour and weapons – so that this simple equipment can always be equipped in any unit template without having to have it in stock.

I’d suggest that “Iron”, “Leather” and “wood” be deemed to be the standard and receive +/- 0.   Which means all players can design units with standard gear and no bonuses without the need of extra resources or micro management.

But advanced resources – Mithril – adamantine - dragon Hide  - Yew Wood - whatever – have bonuses.  Mithril armour deflects more than Iron and a Adamantine sword does more damage than Iron.  So the players who want to micro manage and train higher level units or create higher level equipment can. 

This also creates a more gentle learning curve for the game.  A novice player might play with all Iron equipment but then slowly learn more and more about crafting and training and create more advanced units.  The AI on computer opponents could be set so on Normal they use standard training and equipment but on hard the AI opponents start to take advantage of training and on very hard the AI uses special training and crafting or something. 

I prefer option A.

If you don't have mithril mines, you damn well better not be building units equipped with mithril weapons. Unless the resource system is more complex and 'units' of mithril ore have to be harvested and can be stockpiled, in which case, you can only build the units so long as you have units of mithril ore.

This way i won't feel so horribly 'cheated' when i brilliantly destroy the opponents mithril mines only to see hordes of dread knights continue to be churned out simply because the opponents have such high industrial capacity that it doesn't actuallly need the bonus from the mines to produce mithril equipped troops.

Secondly, this avoids the problem of having hordes of dread knights but each with some missing individual components. Unless there is some really brilliant UI to display the units equipment, digging through you stacks of units trying to make sure that all of them are fully equipped before taking them to battle is a lot more annoying then just having some backup designs that you could fall back to when some resource is lost.There should then be an option to just upgrade this lower tier units to the higher tier units once you secure the missing resources again.

Managing designs rather than individual unit equipment is far more easier IMHO. Having an intelligent 'family' or 'class' based design system is a better solution. You should be able to design 'families' of units. It should then be a simple matter to upgrade units in a particular family to their higher tier variants in the same family when the resources become available. Simple design controls such as 'add this equipment to all designs of the same family' will allow you to be able to quickly upgrade all your related designs to the latest tech rather slogging through each individual unit design.

Option C, but with an AI backup.  You know you can . 

The player is informed of the discrepency, but there is a background manager that replaces key equipment with a comprable item that provides at least a percentage of same benifits of the now missing item.  The discrepency should also be highlighted on the 'build' menu in case the player forgets exactly what 'part' the message had announcd now unavailable.  Raplacement remains untill either the player saves the new build as final or resource resurfaces.

On a side note regarding the system of equipping items, i'm not sure if more neccessarily means more fun. For instance, would i find it fun to to have to individually specify helmet, body armour and boots? Unless each item has a lot a variety to it, it may be meaningless as you would most often just equip the highest tier helmet, body armour and boots anyway. Example, would there be any instance where i would NOT want to equip mithril helmet together with mithril armour?

And as with some comments, skills should also be able to be 'added' to a unit at higher training cost and time. I don't see how else you would be able to create say scout units with wide area of spotting. I can't imagine any equipment that could impart scout skills, unless maybe with magical ranger's cap or something funny like that.

Yeah, I think I like this idea.  If resources are produceably in quantities and storeable, then it will give some very meaningful dynamics to your trade arrangements with other players.  You could create arrangements with other players that would flow to the effect of "give me 200 of resource X every turn and I will give you 100 of resource Y every turn," with numerous resources at the table for negotiations.  Imagine, for a moment, an empire bestowing a close ally with 10 fully refined, hero grade Runed, Fire-Mithril Long Swords as a sign of their eternal friendship.

Or, for instance, you could make an arrangement such as, "I will give you 100 units of Feather Iron for every turn you spend at war with Empire X and/or for every unit-of-successful-warfare you have inflicted upon Empire X.  Some interesting diplomacy could emerge from such a system.  As I believe Den mentioned in an earlier post, though, a system where specific resources could make for differing attack/defense values in otherwise identical units (in the event that you lose the resource) could make things very confusing. 

I imagine it couldn't be too terrible, though, if you simply had "Death Knights" with, say, slightly larger or smaller sword icons over their batallions to represent their differing attack powers.  

My greatest concern in reading about this system is the possibility that rather than fostering "interesting decisions" it will rather promote "no-brainer decisions."

One avenue of thought related to this is the potential universal utility of the bonus equipments. I begin by assuming that there will be an upgrade system (that is, if you discover magic honey somewhere you can upgrade your existing guys to use it) of some sort since that type of thing is generally logical and fun for players to use. A good upgrade system should be consistent in form of payment between what adding something initially vs later as an upgrade. For example, if the only thing adding magic honey to the initial design of a unit does is add one turn to its build time, then upgrading an existing and otherwise the same unit should similarly take additional time in a city.

The way the current system looks to be developing, it appears that adding equipment will possibly add no or virtually no additional cost to the building of a unit. This means in practice that a dread knight without potions of valor will take the same amount of time to build as one with them. And that's a rather reasonable view also with nothing inherently wrong with it. If the potions are sitting there already made, why should it take longer or cost more to hand them to the guys as they leave the barracks?

The problem subsequently created though is that the bonus equipment then firmly enters the realm of "no-brainer" decision making rather than "interesting" decision making, at least related to the unit design and upgrade process. If there is a ready and sufficient supply of valor potions, shouldn't they be handed out to everyone that can use them? After all, the cost associated with using items like that is in their initial manufacture, not the act of handing them to guys in the field. In game terms, if the cost to upgrade to use a certain piece of bonus equipment is negligible, then of course I should upgrade every unit I have to take advantage of such a bonus.

One solution to this could be to model the restricted availability of specific potions or flavors of honey on one or both of the raw material and manufacturing levels, meaning that only so many of your troops could get each thing. This strikes me as a micromanagement nightmare of the highest order.

Another solution that appeals to me on a gameplay level would be to one automate and mandate that indeed all of your units receive the best and most potions that they can. However, your nation would only have a limited amount of bonus material to distribute and that level of availability compared to the number of troops you have would determine the magnitude of the item's bonus that applies to each of your units.

In essence, most bonus items would be reimagined as variable level consumables rather than one time attribute modifiers. This would nicely solve the problem of what happens when you are cut off from a resource node. Just lost half of your available magic honey? Then your units only get half of the magic honey bonus they used to get. They're the same units and no micromanagement is introduced at all on a unit level. The idea could also be further expanded to incorporate a type of supply system where units that are somehow determined to "be out of supply" would no longer get their consumable equipment bonuses.

Anyway, this post got rather long, so I should probably stop. Thanks for sticking around if you got this far.   Hope some of the ideas are marginally useful.

These are the solutions I'd want.

Being good at storing vital resources should be a part of the strategy in the game.

When you capture a caravan or a city, the resources you undertake will be sent back to your nearest city by a caravan. You may choose to escort it......

Stockpiling (saving for a rainy day) resources are great fun, and cities with huge stockpiles will be vital strategic depots in war.

Ergo: Make it a system that requires certain resources to build certain equipment, but make it possible to invest in huge storing capacities, and let all cities have a minor standard income of all the most vital resources each turn. To store this income they need at least one warehouse.

Yes, NuclearEngine's idea would be great: Decoupling the unittraining from the weapon/armor forging.

Building a unit process:

1) separately design your unit equipment sets, forge and store them.

2) train a peasant as an normal/experienced/elite mililtary unit (you also should have some options here ... e.x. a cavalary, ranged, melee, scout, etc... unit )

3) select a stored equipment set for trained unit (of course this step could be automated)

4) if a resource isn't available you won't be able to forge the set and get a notification

5) if a set is not available you get a notification and could choose an alternative 

Of course you could even forge and store weapons and armor separately (not as sets) but  this would be to much micro management (for my taste)

Greetings

While option D does sound ok, I think I should propose option E:

Option E: Unit designs are only a shortcut, unit designs are simplified, and basic resources are stored.  When you want to build units, it shows you what metals/wood/stuff are available in this city, what can be imported from inside your empire and what can be imported from further away.

When you decide to build units, you just pick one option for each of the five slots: left hand, right hand, armour, mount, training and special.  E.g. Steel pike, nothing, bronze banded mail, nothing, normal, healing herbs.  The pike would give the unit 'negate first strike', but is two handed, materials give bonuses/penalties to attack/defence, and it would use the herbs to heal faster.  The time it takes to build is the maximum of crafting + import time and training time.

If you pick a design, it auto-fills the slots that it can, auto fills the name field, and shows the amount of time required.  Then you just adjust it to fit, if necessary.

If you lose a resource while the unit is being made, it can be assumed that the resource is already at the city, for simplicity's sake.  Units further on in the queue will be cancelled, and the player is notified.

This way, you could build wood club peasants if you need them, without having to have a design for them, but you still get the advantage of having designed units.