Thanks QES, I'll give the Battle AI a try: 'till now I left it on a to try list waiting for it to be better ironed out, as I see some strange behaviour reports, but it can't hurt to give it a shot
As for the HP for units - there's a serious issue you forgot about, if you don't also increase dmg all around: insta-heal promotions. If you increase also the dmg units do, you'll further encourage using units built from a barracks building which grants HP bonuses, as "standard" units would be extremely frail. If you don't, every 4-5 battle turns both the attacking and the defending units will keep magically healing themselves. It already happens very often - as the AI definitely favors that promotion while the unit is engaged - with x2 HP it would be a nightmare, definitely not fun.
Also, the survivability advantage the player already has thanks to his common sense, makes it so that while the AI wastes its units the player tends to grow some very experienced, overpowered units that become pretty much immortal. As the AI would still be suicidal (embarking under the nose of your destroyer, sending a lone unit to be slaughtered by your citadels without first trying to soften you up from afar with ranged units, fortifying a unit instead of retreating it even when you have several ranged ones that are making mincemeat of it, etc), this advantage would be even easier to achieve with 20HP units that would survive even when you make a mistake and advance 'em too hastily into the FOW.
20 HP imho is far too much. I would go for a +1 for each building of the barracks tree that is present in the training city, and maybe another +2 given by the Heroic Epic national wonder, so that you can reach max 13 HP per unit in a "normal" city (which is a 30% increase, quite interesting), 15 HP in your main training facility, that would on the other hand probably be way behind the frontlines in the late game, so you would have to take into account also the time needed to send those elite units where the action takes place. This probably wouldn't require a wide rebalance of DMG all around, maybe just some buffs to city defenses to avoid making conquering too easy both for you and for AIvsAI scenarios. Or using the active city defense mod together with this, which would be just perfect.
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Thal, another thing I found myself wondering about after my last game: the GDR is really dull. I mean, I've nothing against it per se (after all I play Japan most of the time
), but I feel it lacks the "holy crap this thing is the big mama of all badasses" feeling when you, aswell as your enemies, can actually have several.
Would it be possible to make it somewhat like a wonder, so that there can be only one in the game? The civ who builds it will have a great unit, but once it dies it is forever (as such it would need some buffing, like enabling defensive bonuses et cetera, so that when the one who built it is an AI it wouldn't go to waste as soon as the AI decides to go on a suicide run): it would make it feel unique as it should, and instead of being an I win button it would actually require you to be careful and keep it under escort (especially while embarked). Aka, more
balanced