A variant on Option C - what if there is an automatic back up option that's always available?  So for example, if Mithril is unavailable, then the player starts getting units with normal Long Swords and helmets, rather than the nicer, shinier ones.  In the case of the Twililight Honey Pack, perhaps they just lose the bonus.

edit - This way, a player loses a valuable bonus without being forced to redesign their units.

When this happens, the player can be informed of the lowered quality, and the reason, but they're not forced to redesign anything immediately (unless they want to, of course).

This way, a more casual player knows what's happened, and can just get on with the game. Alternately a more hard core gamer knows to jump in and tweak the unit designs.

A possible tie in to this would be to have a 'grace period' after losing a resource that represents stock piles being used up.  So for example, I lose my Mithril mines, at which stage I'm notified that supplies are running out, and I have (say) 10 turns to recapture the mines before my troop production will be affected.  This adds a number of interesting choices to a game - do I continue as planned, or retake the hives I just lost?  Do I target the enemy's army, or reduce his production ability so that his Dread Knights are less fearsome?

I don't remember which economic model was going to be used for starters...

I'd favor A mixed with C. I mean, if you don't have mithril, forget about those nice mithril armour pieces and swords. (no more Dread Knights for you) You should get a warning about substituting pieces if je still wants to build them but... well, that would be like a new unit. If instead of the lack of mithril we talk about the lack of twilight bee apiary (why do I get the feeling that some bees at Stardock are going to be in the credits of the game?), then you can still build those Dread Knights without it (ok, you could build the Dread KNights without the mithril but they would go without weapon or armour...) because it's just an extra.

Out of curiosity: the Attack, Defense and HP... is there possibility of changes/evolution? Like adding other stats (no need to get hyper realistic but yes more varied) and/or skills. Not that I don't like the simplicity of the current system.

Edit: damn me. Forgot about that if you lose a resource (mithril in this case) but it's not just a bonus but you actually get to store quantities of it... well, you have your buffer there until you reclaim the resource again.

I would just like to chime in with Winter that, as nice as simple attack and defense is, we really need more stats. If nothing else we need resistance for each element. (I think of it as in GalCiv2 defense vs lasers/missiles/projectiles.) I think that if this is not present, then the diversity of the elements themselves is lessened, it makes all the units too vanilla.

Adding another step into the economic model would help this senario out. For instance:

Mithril ore is used to make mithril armor that can be stored in a warehouse.

These armor pieces are then used to make troops.

If you lose the mithril you can still make the troops for some time but will have to get back that mining node for future production (or start trading for some armor).

Your notification feedback would come from a blacksmith that says "I have run out of ore".

I think you can merge options B and C.

When you lose a key resource you should be given proper notice of what that means. If you're building multiples of the unit in may need to pop up a screen saying that you only have enough of the resource to produce the object in one town... slowly. Would you like to substitute a different item instead? How much of the material is in storage across the kingdom/empire for the building of a last few units with it?

Personally I also find it painfully difficult in 4x games when a resource is lost and suddenly all production on a unit is lost because you don't have the resource to complete it and must start over. So whatever you do please don't go with Option A.

Why not go a simple route? After the resource is lost the player is given ten (or whatever) turns during which thier "stockpile" allows them to to continue building the units. After the time is up, give them the option to modify the units to make them legal or make an entirely new one.

That or the unit just takes longer/costs more. Thats super simple, and may be the best option.

I like C, though I'd like to see some of B mixed in. For nonessential items - like your honey that adds 10% hp, etc - C is fine, if access to the item is lost, just build the unit without that bonus (although it'd be good to inform the player that the 10 dread knights he just queued up will lack that bonus).

For items that you don't want to simply leave out, like armor and weapon, I'd prefer B; to see the unit still get built without the resource, just slower. If your unit uses an iron sword, and losing access to iron means you either have to redesign a new unit with a bronze sword (A) or choose a replacement sword when you try to build the unit (C), either way it's painful micromanagement. And not just micromanagement when you're training the unit, but it creates more micromanagement later - units with iron swords may perform noticeably better in combat than otherwise identical units with bronze swords, so you now have to keep track of which units in your army use iron and which got the bronze, perhaps relegating the bronze sword units to city garrison or acting as a rear guard over your supply lines, while the iron sword units are the front line, first to attack. This may sound fun and tactical, but multiply it over potentially hundreds of units, and it'll just be a pain - for simplicity's sake I'd much rather know that every unit of a given type has an iron sword, even if it takes longer to build them without access to iron.

A good number, I think, is 2x build time without the resource; i.e. if my soldier with an iron weapon and iron mail normally takes 15 turns to train, he should take something like 30 turns to train without access to iron. Of couse it's more complicated than that, what if he uses an iron sword but leather armor and you lose access to iron? However the details work out, though, I think it should wind up taking about twice as long at the most without a resource. This is a big difference, it makes you want to get access to iron, but not such a massive difference that it's no longer worth building the unit if you lose access to the resource. Keep in mind that, if you temporarily lose access to iron and you need units asap, you always have the option to build an older bronze design - but unless I'm desperate, personally I'll stick with building the iron design half as fast and focus on getting that resource back.

This is a great idea too, it lets you get all your units back up to standard later if you temporarily lost access to a resource, so you don't have to worry about some units of the same type having different stats (which I'd really like to avoid having to micromanage).

This is how I'd like to see the resources handled, as it was something that always struck me as missing from Civilization - my mighty nation was completely shut down in the later stages if I lost my oil fields. Now, this made them a great strategic Target, however it didn't make any sense that I wasn't able to somehow prepare for this.
Perhaps adding a Warehouse Building that enables a small percentage of a resource or produced items to be stockpiled when not being used in Unit production would be the best method? This ensures that your not able to stockpile thousands of items and keeps resources' strategic value, while also ensuring that losing your only available Iron Mine, for example, doesn't completely remove your ability to muster some kind of defense.

I think it kind of depends on how resources are handled in the game. Do you harvest the resource and stockpile it (or the products made from it), or do you simply have it available and use it on demand? Does each city need their own resource for making gear for units from it, or is it empire-wide or regional?

The next question is how easy/hard is it to lose that resource? Are resources generally located far from the cities that use them? How likely are you to lose a resource in the first place; does an enemy need to invade deep into your territory to capture the resource or is it located so far from cities that guards/reinforcements will take a long time to get there in the event that the resource is lost? If it's deep in your territory odds are that either it's a raiding party you can somewhat easily deal with,or it's a part of a larger invasion and capturing the resource is merely a part of hampering your ability to reinforce your lands.

What I'm trying to say is, the amount of "hassle" that comes with losing a resource should be somewhat related to how easily it can change hands to begin with. If an important resource is likely to change hands quickly and often, the impact on unit design should preferably require as little micro-management as possible, and preferably it should automatically change to a backup-design or something. This is doubly important if losing one resource impacts multiple cities, since a resource changing hands often resulting in you manually changing building orders for multiple cities every other turn is a recipe for tedium. Mulitply that with the number of different resources a unit can depend on.

If losing a unit resource is a major thing that is unlikely to happen very often, then some micromanagement is less of an issue since there's likely several actions the play will need to take anyway in order to deal with the issue.

Hmmm, that was very general and uninformative. Sorry, I'm better at playing games than designing them

Option C is more work for Stardock but other then that I can't see a downside.

+1 vote for Option C

Sammual

I kinda thought this question was tied up in the resources part of the game.  My understanding was that since caravans were moving resources from mines/bee apiaries all the time, there was at least some of a given resource heading to a town at any time.  Those resources would start into motion when you made a build, that would (invisibly to us) start to move iron/bees/etc toward the town in which the unit was being built.  The upshot of this was, to deny a player building the Honeyed Warrior O' Doom you think he's building, you need to control the mine, the apiary, AND hunt down and kill his caravans before they get to the city.  You can't build any more once the resources are depleted, of course, but there's a time lag between when you take control of an opponent's mine and when they truly can't build a unit requiring resources from that entity, because some of the resource is alread enroute to his cities.

Am I just woefully behind the times on the thinking now?  I know we chose (at least initially) a simplified economic model in the other thread on economics (Stardock Dainty Underthings Made Public, or some such thread), but I thought that caravans still were part of the game, moving resources around between towns.  Heck, I've even seen the little wagon wheels in the build we have. 

I agree with Draginol that option C is the best, but the above point should be addressed: IMO the incomplete Dread Knights should "run around" with a marking that makes the player realize their weakness, but should also be auto-upgraded as long as the resource is recovered by the player and kept for a certain number of turns. (having them go back to a city to upgrade would be more realistic but quite tedious IMO, I hated having to do that in MOOII with starships).

So from my understanding of how resources will work, you can build warehouses in cities, and use them to stockpile resources (that is how it's going to work, right? That's what I remember, anyway)

Assuming that's how it will work, then I think you should be able to build the unit so long as you are producing/mining the necissary resources, or you have them stored in warehouses. If you have been stockpiling mithril since the beginning of the game, but then you loose your mithril mines, you can still build units using mithril, at least until you run out of stockpile. If/when you run out, I'd go with B or C.