As many have pointed out, the supply factor is a key to a really good strategy game. Why then have so few games attempted to include this feature? As far as I can tell, the reason is complexity: it results in excessive micromanagement that overwhelms the average player ('average' only in the sense that they want a game, not a simulation). There are a few ways to implement this in a game like 'Civilization' (i.e. each item reduced to single grid square). These are the ones that I am aware of:  Units carry x # of supplies and must refill every so often at a city. Divided into at least 3 parts: a) Supplies: Food; # of turns unit can stay outside friendly territory. b) Fuel: Resource: # of MPs unit can use outside friendly territory. c) Ammo: Resource (?): # of times unit may attack outside friendly territory. Possibly also including 'Freight' unit that can refill unit on the spot. Seems to be the simplest in terms of concept, but certainly not micromanagement (i.e. the greater the number of units, the more work the player has to do in terms of micromanaging the units). Possible Solution: AI takes over a unit that is about to pas it's point-of-no-return, thus the unit would automatically go back to the nearest city and refuel. This would decrease tedious micromanagement significantly but would also increase processor requirements when there are many units on the map.  Units function within 'Supply Area' (see a related thread in the 'C3C Requests' forum). Supply area consists of a base (usually a city) and a border that extends from that base according to the unit's range capability and it's fuel requirements: a) Range: Determines how far the Supply Area border extends from the nearest base when that unit is selected. b) Fuel: Base must be connected to required resource, otherwise no Supply Area will appear when unit is selected --if base is disconnected from resource while unit is outside the base (somewhere within SA), unit becomes immobile (?). This is MUCH simpler in terms of micromanagement only it suffers where ships are concerned as ships tend to travel in a straight line across vast distances rather than being refuelled within a certain area (i.e. ships are limited to operating within SA --if ship's range is set too high it will have too broad a reach from single supply and the strategic element of supply significantly decreased). It is also somewhat unrealistic since units are able to operate indefinitely within SA without having to physically go back to base. Possible Solution: units can move beyond SA but will gradually lose health if they do so.  Units must be loaded into armies in order to survive outside friendly territory. Army is able to supply via Roads (i.e. while on or adjacent to a Road that is connected to a friendly city, an Army can Survive outside friendly territory. This requires less micromanagement than  but limits the mobility of units not loaded into Armies. This also clearly cannot apply to ships, which means such units would have no limitations. Notes: The reason why I put so much emphasis on including ships into the 'supply' argument is because strategic ports of call that allow ships to re-supply/refuel/rearm have always been of great importance --colonial empires would never have evolved had it not been for strategic ports. If ships have no supply limitations this important factor becomes useful only in the sense that it allows ships to heal there and nothing more. Clearly these systems are not mutually exclusive and can be mixed as necessary. If  is to be taken seriously, the question of whether it is feasible to automate units when they are in need of re-supply is really the determining factor. I think that if I were to choose, I would keep  and add  to it: Units are limited by Supplies, Fuel, Ammo but cities extend a limited Supply Area around them (not to be confused with borders) so that units can function within that area without re-supplying, refuelling or rearming. The idea in  of Armies extending supply is also good so I was think of giving Armies a really high Supply value --all other units' supply limits are overridden by the Army's (i.e. all units run out when the Army runs out --alternatively: if Army runs out, it disbands and all units begin consuming their own supply independently of each other). Another solution to  is the concept of 'living off the land:' units on or adjacent to food-producing terrain can partially re-supply there. I think it would be the dream of most of us to see some kind of supply factor included into 'Civilization' regardless of how simplified. How? See above or add your own stuff. I'll post this in 'The Official Civ4 Ideas Thread,' but I think the concept needs some cleaning up first. The biggest problem is reducing micromanagement to a level that will not take away from the straightforward combat experience of Civ3. If you have nothing to add, just tell me which of the above alternatives (1,2 or 3) you like best.