Alright, here's what I've distilled from reading through the recent pages of this thread. Thanks for all the feedback on my initial list. Hopefully I've done justice to your excellent ideas; please let me know!
Sea Units
-
Armored Frigate (available with Astronomy + Military Science + Steel): 120
, 12
, 4
(+2
with Steam Power), replaces Ship of the Line.
-
Dreadnought (available with Astronomy + Steel + Steam Power): 180
, 20
, 4
, deals collateral damage, 50% withdrawal chance, upgrades to Battleship.
-
Torpedo Boat (available with Combustion): 140
, 20
(+50% vs. Submarines,
cannot see Submarines), 6
, gains 2 first strikes, upgrades to Destroyer;
cannot bombard defenses.
-
Transport (available with Combustion): as normal.
-
Destroyer (available with Artillery + Combustion + Radio): otherwise as normal.
-
Battleship (available with Artillery + Industrialization): gains a 50% withdrawal chance; otherwise as normal.
With Rocketry, all ships gain access to "SAM 1 / 2" promotion which gives +20% / +30% interception. Bombers lose their anti-ship penalty. Fighters gain the ability to spot Submarines.
- - -
Land Units
-
Bombard (available with Gunpowder + Metal Casting): identical to Trebuchet, identical cost, upgrade to Cannons.
-
Culverin (available with Gunpowder + Engineering): 100
, 10
, 1
, siege which
cannot bombard defenses, upgrade to Cannons.
-
Early Armor (available with Combustion): 120
, 20
, 2
, armor unit, no defensive bonuses, upgrades to Tank. Nothing upgrades to this unit.
-
Elephant Machine Gun (Khmer UU, replaces Early Armor, requires Ivory instead of Oil): just kidding.
- - -
Desired Effects
- Gunpowder now a "destination". It's possible to invade a neighbor with just Muskets and Bombards. If you have Janissary or Oromo, it might even be a good idea.
- Combustion remains militarily strong, but it's not the "one-stop" own-the-seas tech it used to be.
- Battleships (and Dreadnoughts) become the Siege of the seas. They deal collateral, the only addition necessary was the Withdrawal chance. Hopefully this will make Battleships a thing you seldom lose but often need to protect (by sacrificing your "screening" ships).
- The deal with Torpedo Boats getting a bonus vs. Submarines is purely a game issue. Torpedo Boats should be on roughly even footing with Subs, but Subs should murder Dreadnoughts, and Destroyers should murder all of them. Adding this one special bonus allows me to get the desired effect with zero changes to existing unit strengths.
- Early Armor is
an answer to Infantry and Machine Guns. It's also a way to actually get some value out of Anti-Tank and Panzers, who should stomp it flat.
-
Small Unit Impact: this only adds 3 new sea units and 2 new land units (plus one alternate "skin" for an existing unit). The tech tree itself is unchanged, but some units get pushed back to make room for the new ones.
Please let me know if I've neglected anything interesting, or made some kind of balance mistake.