Interesting ideas. Let me just think out loud here for a while.
While it is true that "farms produce food" -- for early-mid medieval Europe the farms were not that productive, and most of the food was used for subsistence. In the civ model, food produced on farms is used to grow cities/population. Specifically, the excess food for a worked plot (beyond the two food necessary to support that person) always goes to population growth.
So I think it historically appropriate to limit the food from farms until the introduction of
crop rotation in the late middle ages (for Europe) and the
Muslim Agricultural Revolution of the 9th century for Islamic civs (perhaps with a tech like Arabic medicine, which currently is fairly cheap and requires only Arabic knowledge, so the Muslim civs can research it quite quickly).
Does this make for good gameplay? Ultimately we would have to see, but I think we can reason about it a little bit. Cities still get surplus (>2
) food from pastures, farms on grain resources, and seafood. Windmills on a grassland hill would also give a surplus
(though windmills come a bit early in our tech tree). But if farms don't give food, is there any reason to build them? If we stick with serfdom+manorialism giving +1
and +1
then farms (with an initial +1
) are an okay improvement, but I might prefer to skip serfdom and spend my people on a cottage (which will grow) or a mine (which is already pretty good). Still, for a quick starting boost the farms are the best improvement you can make, and many cities will have a grain resources which requires a farm anyway, so skipping serfdom means you're missing out on those "free" hammers and commerce.
Okay, then how might we work the mechanics? We could:
- Drop the farm food bonus and give +1 with Arabic Medicine.
- Place the +1 bonus elsewhere in the tech tree, somewhere a bit earlier, but where the Muslims can still reach it first. We could make it have an OR requirement so that you either need Plate Armor (say) or Arabic knowledge.
- Make the default Economy civic (decentralization) ALSO give -1 to farms, just like manorialism. This is sort of equivalent to pushing the food bonus back to whichever tech enables the next economy civic, but a rather different way to achieve that end. Of course, then smart players will switch out of manorialism ASAP.
The reason I'm tempted by this idea is because I think it is desire-able to reduce the magnitude of the invisible coded growth/production rates between the civs and achieve our balance/history goals more through terrain (forests) and starting techs. With these changes we could bring down the penalties on the starting civs (particularly France/Burgundy and Byzantium).
@BurnEmDown: Here's how to do it if you want to experiment. Make a backup copy of RFCEurope/Assets/XML/Terrain/CIV4ImprovementInfos.xml and then edit that file.
Here's what the farm entry currently looks like:
Changing the following lines will change farms from +1
to +1
(changed values in red)
Code:
<IrrigatedYieldChange>
<iYield>[COLOR="Red"]0[/COLOR]</iYield>
<iYield>0</iYield>
<iYield>[COLOR="Red"]1[/COLOR]</iYield>
</IrrigatedYieldChange>
Then replace the line <TechYieldChanges/> with all of these lines to give the +1
bonus on Arabic Knowledge.
Code:
<TechYieldChanges>
<TechYieldChange>
<PrereqTech>TECH_ARABIC_KNOWLEDGE</PrereqTech>
<TechYields>
<iYield>1</iYield>
<iYield>0</iYield>
<iYield>0</iYield>
</TechYields>
</TechYieldChange>
</TechYieldChanges>
.
and +1
resources and building. This would requires some additional pruning of map or buildings by someone (possibly me).
roduction/Late Game). 
