Additionally, I think that (as compensation for losing their civ power by late Rennaissance), have forests give +1 food or something.
(perhaps to symbolize the high population density of the Celts in primarily forested areas)
Well no, not on the UA, but if one wanted to remove one of the UU's (i'd recommend the swordsmand that heals after it attacks, the early scout movement warrior is pretty cool imo).
Then we could have a UB to come in and provide say this bonus.
Woodland Forge(for the lack of a better name) - Replaces forge
Cost : 180 Hammers (30 more than forge)
Maintenance : 3 Gold (1 more than forge)
+2 Food
Forest Tiles give +1 food
New Melee Units start with Drill I
New Ranged Units start with Barrage I
This way the UA and UU work together for early bonus, then the UA continues until it runs out in the late medieval era, when the UB kicks in which will provide some smaller bonus for the rest of the game.
The UA can then run out of pace at Metal Casting. When the UB forge becomes available, all units lose the initial blitz promotion, all new units come with Drill I or Barrage I, (+20% for rough terrain). Which would keep to the Forest theme.
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This allows for a cool, blitz promotion early on, (if you make sure its blitz and not attack twice then a horseman with 4 movement points is capable on making 4 attacks, which makes it even more cool), which only lasts till the tech after Iron working, but you can avoid Metal casting for a while and keep it if you wish too, Technically you could go all the way to biology without taking metal casting, but you would get hardly any military tech improvements which is the important bit, you can keep blitz but not progress into crossbows/longswords/trebuchets, you can get knights though ^>^.
In the late game, having a free Drill / Barrage promotion will be pretty cool, 1 level up to spend elsewhere. Using a baracks and armory, you can go straight into some more advanced promotions like siege on ranged units.
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The alternative to having a UB to add something to middle-late stage. Is to keep the two original UU's, but change the UA so thats its more generic, like +1 movement or something. Which is pretty useful but not 2x attacks useful.
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Also as for single unit graphics, some of us like multiple unit graphics and may want to use your mod, how about inserting the "single units" as an option on the menu so it can be toggled on and off.
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