Hello!
Here are my few suggestions for all games - from Vanialla to BTS:
SMALL THINGS:
1. Have airbases like in CTP2, where you can rebase your planes to airbase tile improvements.
2. It always strikes me why modern battleship cannot attack several galleys for example. Essentially I mean blitz promotion (or equivalent) for all modern naval units, some planes.
MEDIUM THINGS:
1. When you have a lot of hammers produced per turn in a city, and say you are building a unit that costs at least twice as little, produce to units per turn, not one! For example your city produces 100 hammers per turn, you build a unit that costs 40, so produce Math.Floor(100/40)=2 units, then 100 mod 40 = 20 -> would be contributed to the next turn's production. Otherwise in the later game especially there is no point to have super hammer producing cicties, if you have built all buildings and wonders already.
2. I came across the fact that your treasury may be getting crazy money - anywhere from +10 to +2000 per turn, yet your science research is at 100%. Especially in the later games - you have all units upgraded, science at 100%, and you have like 30000 in treasury, with +500 for example every turn. Why, in the world Vanilla, Warlords, and BTS would not allow you to increase spending on culture, and espionage, while your science remains at 100%? Or even better increase science to go beyound 100% ? I mean you have the mopney still and have a lot more! Extra +500 per turn, so use it, instead of hoarding it in treasury!
3. A slightly different thing to #2 - suppose you have big treasury, but say per turn you are not making a lot of gold - only +10 for example, however you really need to research certain tech ASAP, so you should be able to use TREASURY for that, so inflate tech spending to 200% or 300% or whatever untill your treasury reaches 0, and you have no money left to spend on rteasearch that way. This way you 1) take advantage of treasury in a practical way, and 2) research techs faster.
4. Well #3 brings another point. Add another property to all techs that would determine a MINIMUM TIME (in turns for example, depending on map size and game speed, plus mutiplier or something) required to be spent on researching a technology. This way even if you have huge amounts of money - you will not be able to reseach any tech in just one turn! For exmaple consider this case:
treasury = 5000
treasury increase = +100/turn
science spending @ 100% = 1000/turn
actual science spending = 300% (the feature I proposed in #3)
tech to be reserached cost = 5000
percent of this teched reserarched already = 0%
minimum research turns required = 2
after turn 1:
treasury = 5000+100-(1000*(3-1))=3100 -> starting treasury + treasury increase per turn - (science research @ 100% * (actual science reserach [300% that is ] - 100%))
treasury increase = +100
science spending = 100% = 1000/turn
percent of this teched reserarched already = 62%
5. Though it should be possible to research some techs even within a turn, or even 0 turns! Just as what I proposed in #1 with respect to units and hammers, should be done to techs and beakers in some cases. Suppose your science output is 8000/turn, you are reserachning tech that costs 4500, and then plan to research another tech that costs 2500. Well 4500+2500=7000 < 8000/turn (what you have) -> thus research TWO techs in one turn (provided of course 1) these techs are allowed to be researched in just one turn, and 2) you meet all requirements for those techs).
6. There should be a much better thing than Blitz promotion. It's too simplified for the concept of attacking multiple times. Instead, it should not be a promotion at all, but rather some special characteristic of a unit. I DO NOT PROPOSE adding another property like "attacks per turn=3" to a unit. Instead I propose something more realistic and sophisticated, but not terribly difficult to implemet: AttacksPerTurnPoints. So, if Battleship for example has 100 AttacksPerTurnPoint, while galley has only 5, Battleship can attack galley 100/5=20 times (as long as it has health obviously, and move points left), while galley can attack math.ceiling(5/100) = 1 time. I am not sure if this is the best implementation, but the ide is that NEITHER Blitz (with its limited availability, and attacks = to number of move points), nor simply "AttacksPerTurn" property are adequate, because thse approaches do not take into account which unit attacks which unit, which si important as there's a tremendous difference between say tank and maceman, not just in their power, but in their manuverability. Which actually brings me to another idea - these AttacksPerTurnPoints should be offset by a multiplier, depdning on terrain - you cannot expect a tank (at least eraly tanks) to operate well if at all on mountains or hills... so, obviously it should not be able to attack more than once then.
Another example: howitzer vs catapult, clearly howitzer can have more mnuverability and hence AttacksPerTurn than catapult. However even catapult vs some units, may outperform in this area.
7. Great farmer, famremer specialists
8. Factory/somethings imilar tile improvement.
9. Spend treasury to produce hammers, food (may be?), and great people points - the SAME WAY as now you can spend it to produce scince, culture, and espionage in BTS. All what I said in #2 and #3 in this section applies too.
BIG / CONCEPTUAL THINGS:
1. Composite respurces. Example: Copper + Tin = Bronze, where copper and tin, would be the ones available on the map, once certain tile imps and techs have been constructed and researched, while Bronze would still be a STRATEFGIC RESOURCE, however proiduced by... and here's where creativity comes in - either by naional wonder, or may be even by a building such as bronze smith... or whatever. The number of composite resource (bronze in this case) produced should depend on the avilability of component resources - copper and tin. If fo example 1 bronze requires 1 tin and 1 copper, then if you have 2 tin, 2 copper, and 2 p[roduction facuilities, you will produce 2 bronzed, but if you have 2 tin, 1 copper, or 2 tin, 2 copper, but 1 prod. facility you will have 1 bronze, and remanining 1 tin and 1 copper available to you (for trade to other civs, or other needs) UNTILL you build second prod facility (you may decide not to, - you may want to help a frindly civ which has tin, but n copper, while you have 2 tins, 2 copper, and 1 bronze prod facility -> so send 1 copper to that friendly civ, so it too can produce bronze).
You can go even further with this by for example saying that 1 bronze = 1.5 tin + 1 coper. In which cvase you will need to have at least 2 tins, and 1 copper to produce 1 bronze, and if you have 3 tins and 2 copper, you will produce 2 bronze (provided you have 2 bronze prod. facilities). However I think it's too complex, and in most cases 1+1, or 1+1+1 should suffice, as otherwise it may be very difficult to produce composte resources on small maps, with few natiral resources available.
It should be said that composte resources can be constructued using both natural and other composite resources, and they can be all strategic - happy, or bonus. However when you do consume a resource to produce compiste resource - the intial resource that you consume (copper and tin, in case of bronze) are NO LONGER AVAILABLE for your use (for units that require say tin) or for trade with other civs, but you obviously still get hammers, from tile that has the resource. This is untill you stop production of that composite resource - how you stop it - depends - may be add another Industrial advisor - that would overview resource allocation, and allow you to stop or produce composure resources, provided you have needed techs, antural resources, and production facility to produce comp. resource.
And of course just as all current resources - composite resources are available to all cities that are connected by road/ocean/river (you know all that

to a city that has production facility for that comp. resource.
2. Resource allocation. Basically if say Phalanx unit requires 1 bronze strategic composite resource, or if a swordsman requires 1 iron strategic natural resource, that means that building phalanx in one city would consume 1 bronze resource while you are building it, same goes for swordsamn - you are building a swordsman in 1 city and iron is consumed while you are building it. Consumed here means that you cannot trade it while you are building it AND it is not avilable to other cities! So, if you have 1 iron available -> no more than 1 city can produce swordsman unit (or other units that require iron) at the same time! Note that I said 1 city at the same time - not 1 unit - you can even produce 2 swordsman in 1 turn even if you have 1 iron, as per my proposal in Medium Things #1, - that is if enough hammers (and/or food - for mods and civic that allow unit production using food) are available. So 2 iron = 2 cities can produce swordsmen at the same time, and so on....
Another possible twist can be added that would make these resource requirements less harsh. 1 iron for swordsman would mean here that 1 iron is required to FULLY PRODUCE 1 swordsman. SO for example if you have 1 iron but want to build swordsman in 2 cities, well you can still do that but at twise the time.
But an even better approach is as follows: 1 iron per 1 swordsman per turn. So if city 1 produces 40% of swordsman in 1 turn, and cities 2,3 are at the same time building swordsman too, but only at 30% per turn (takes 4 turns to build a swordsman there), it is ok - and all can build swordsman at the same time because 40% + 30% + 30% = 100% of 1 swordsmand for 1 iron per turn. You get it? So there are different ways one can go about it...
3. Reqource quantification - this is probably way rocket scince, but it is to account for the fact that there can be different amount of resource present in different tiles, and also to account for the fact that 1 iron oper swordsman as per #2 in this section is a bit harsh - what if the city that builds swordsman happens to use iron from a huge iron deposit. SO quantofy respurces - how.... well it's up for debate.
4. Same tile can have various tile improvements at the sam time. Why? It's realistic, if you think about to what area 1 tile even on the huge map corresponds to in real life. This same area in real life is very likely to have differnt uses. Of course there should be some limits, and some constraints, so that for example farm with say cottage is not as efficient for food as just farm, but cottage gives you money. However if you take into account forts, air bases -0 those do not take much space - compared to the area of a tile (what it would be in real life), so it makes perfect sense to have a tile with both fort and a farm, or farm and an air base.
Thanks.
George.
PS
Wow - it's probably my biggest post ever
