Let's try a quick list of requirements for a preview v.2
- include equipment supply chain for air units
- how to handle naval upgrades ?
- removing promotion or auto-promote unit (handling "levels" requires a complete new feature has its not open to modding)
- try to fix mid-game massive slowdown (limit the number/range of automated trade routes per city)
- investigate mid game freeze
- rough balance on cost/income
- more basic UI informations
- convert some policies to match the mod's mechanisms
what's missing ? what should be prioritized ?
Sounds good!
Naval units is tricky, since ships are the basis for naval warfare and transports. I'm not an expert in this field so I'd be glad if someone could correct me on this but I have some ideas below:
An easy solution to naval upgrades would be to simply keep the standard upgrade system of paying "gold", but require naval units to be in a Naval city/Harbour to do it.
Ships require expertise and resources to construct and maintain. And rowyers were usually (in ancient Greece) free men who were payed wages to row the battleships. Another reason to keep a standard system of "upgrading" is that I guess you usually needed to build new ship designs from scratch.
A possible design for naval units?
Ideally you would handle naval units and naval battles different from land units. For example you could represent ships as a resource like personnel/chariots/weapons. Meaning that you'd build a "Fleet" unit in your naval city/harbor and within each unit (fleet) you could have varying numbers of ships, ship types (Biremes, Triremes, Quinquiremes), sailors and marines etc.
The biggest difference to a land unit would obviously be that the number of personnel (perhaps being split into sailors/marines) are based on the vessel. Obviously, a ship can be boarded and captured, it can be rammed/damaged or it could simply flee / get lost.
If a ship is sunk, some of the crew of that ship could possibly swim to friendly ships, they can get captured or else drown. (I think I have some data on this in my Google sheets "Naval battles").
Though a ship can also be captured intact and the crew could be captured as well (and made to row the enemies ship?).
A sunken ship would generally mean a loss of the related crew, while a captured ship could directly increase the power of the enemy navy.
If you really want to go for it you could assign each ship a HP /durability that would be initially determined by level of craftsmanship, resources, tech, and then this would be lowered by storms, collisions by accidents, collisions in warfare, catapults, etc.
Damaged ships can "only" be repaired when in port (Naval city/Harbour district). But new ships could be replenished through supply routes (like personnel and equipment on land).
But how big should a fleet/naval unit be?
One way to keep it flexible would be to allow indefinite stacking of naval units. So you could have as many of them as you can support.
About fleets and ship composition I think it makes sense to use a somewhat different system. Unlike other resources, maybe the naval warship resources could require the player to actively build them through City production or a City project.
If the player isn't actively building warships, the City will use its wood and personnel resources to construct fishing and trading vessels more or less automatically.
Though one problem would be deciding how big a fleet should be?
I don't know to what degree fleets in war spent time fishing or raiding coastal villages in order to restock their rations.
Overall it makes sense to me to limit the size of the fleet to the amount of food that your naval Cities can supply them. Meaning that fleets of warships would require a more constant supply line. So there wouldn't be an upper cap of ships that you could have in your fleet, but getting more ships would require a good food supply and actively constructing those ships.
A bonus of having a large fleet should be more/longer/intensified naval trade routes. Maybe even increased fishing?
But what about embarked units?
The only problem with the above mentioned design is the problem that is already present in Civ 5-6, which is that you can embark your land units.
Maybe embarking land units should require having the ship resource in that unit. But since it would be weird to see random land units running around with a warship in their Camp. Perhaps a better solution would be to only allow embarking of land units from a Naval city/Harbour. The embarking land unit would take ships and personnel from the City's stock if available. Since there might not be ships for all soldiers, you could split the land unit and create a new embarked unit, just leaving the land unit drained of personnel and weapons.
The embarked unit could then disembark on another shore, leaving the ship resource on the tile of the landing. Alternatively the ship resource along with sailors could stay on the water tile, and only the soldiers/marines would disembark.
If the ship resource is left on the land tile then any unit going to that tile would capture that resource and be able to use it to embark into the adjacent water tiles.
Although a ship resource for a land unit would also make sense when you want to cross a river or go up-/down-stream.
So an alternative would be to remove thes early era naval units and instead replace them with ship resources that land units can appropriate. But I'm not very fond of that idea myself.
