Attrition

[Hambil]

* When at war all enemy units receive attrition in your territory - Framework in place
* Damage based partly on distance from capitol or perhaps nearest friendly city - TBD
* New promotions to reduce attrition - TBD
* March promotion reduces attrition - Framework in place
* Modified wonders (like Great Wall) to add/reduce attrition damage - some done, more TBD
* Create new buildings to add/reduce attrition damage - TBD
* Make a change to the Honor policy tree to increase barbarian attrition damage - TBD
* Probably create a custom civ with extra attrition as it's UA, or perhaps alter Russia's UA. - TBD
* Add 'Enable Attrition' checkbox to setup screen - TBD
* Recruit testers and work on game balance - TBD
* Terrain affect attrition - TBD

Things that would help right now if you are interested in contributing:
Building ideas.
Wonder ideas.
General discussion on how much attrition damage should be done by what.
Any general discussion on the mod concept and proposed implementation.
Discussion on how to make sure the AI can use the system as well.
Discussion about specific attrition unit promotions (other than march).

As a general concept I already want to impose two things:
Attrition neutrality - for every thing that adds attrition there must be something that removes it.
Attrition cap - set a max for attrition damage that can not be 'stacked' above - not sure exactly how I want to do this yet.

All of the above appear so far to be quite doable, so no road blocks to getting this going soon - as far as I can tell.

Wonders

Spoiler :

Mamayev Kurgan largest attrition bonus in game, late stage wonder.
Afrika Korps removes some general attrition, and double reduction on desert tiles.
Transcontinental Railroad reduces attrition, perhaps by adding a 'supply' promotion to units built in city.
The Great Wall, modified to add some attrition, increased for barbarians.

National Wonders

Spoiler :

National Parks - increase attrition in all cities
Sandhurst - Great generals reduce attrition of units in their radius

Buildings

Spoiler :

Supply Depot - extends the distance from this city to which units are considered 'supplied' and have their attrition reduced. I imagine depending on the map conditions units could get supply bonuses from multiple friendly cities.
All defensive buildings add a small amount of attritution

Unit Promotions

Spoiler :

March - reduces attrition
Supply - increase radius to search for supply depots
Loyalty - increase attrition reduction granted by great generals

Game Mechanics

Spoiler :

Eras - Attrition changes by ERA (becomes less of a factor)
AI smarts beyond flavors - Make sure supply depots and appropriate attrition buildings are being built, and units given correct promotions.
Air units do not suffer from attrition

Improvements

Spoiler :

Field Hospital - Can only be built on un owned land. Acts as a suppy depot.

Civilization

Spoiler :

Name - TBD
UA - Total War: Enemy units gain no bonus for pilliaging territory.

Policies

Spoiler :

Honor Opener - Increases attrition for all civs, especially barbarians.

 

[jeffah3539]

Good idea. I was thinking of trying to create something like this but you can do all the work for me!

An idea I had was that the terrain should play a role in attrition. Ending the turn on fertile lands would reduce attrition while ending on harsh terrain would increase it. This would simulate the importance of foraging for supplies by armies historically.

Good luck getting this up and running!

 

[Hambil]

Not a bad idea. Crossing deserts could be worse than grasslands, by way of example.

 

[Pazyryk]

Keep in mind that the AI will just sit in place if it is damaged and has (or thinks it has) a positive healing rate. I believe this is why barbs will press on in their attack when injured, but other AI players usually won't (though sometimes they will). Leads to some stupidities like a CS unit sitting in one place while slowly being killed by a ranged barb unit. Or worse, an AI force that should be overwhelming getting methodically trashed by the human player because they are all sitting around waiting to heal. It may be best here to take away all natural healing (so the AI doesn't consider it) and then give back hp through Lua only.

 

[Hambil]

Alright... I need to start putting some more detail together. I'm going to start with buildings.

Wonders
Mamayev Kurgan largest attrition bonus in game, late stage wonder.
Afrika Korps removes some general attrition, and double reduction on desert tiles.
Transcontinental Railroad reduces attrition, perhaps by adding a 'supply' promotion to units built in city.
The Great Wall, modified to add some attrition, increased for barbarians.

National Wonders
National Parks - increase attrition in all cities
Sandhurst - Great generals reduce attrition of units in their radius

Buildings
Supply Depot - extends the distance from this city to which units are considered 'supplied' and have their attrition reduced. I imagine depending on the map conditions units could get supply bonuses from multiple friendly cities.
All defensive buildings add a small amount of attritution

 

[Genghis.Khan]

Read Sun Tzu's Art of War, especially Chapters IX, X and XI, to have a Good Idea about the Dangers of Attrition and Advantages and Disadvantages of Terrain. Even if Sun Tzu reflects about many Geographic Entities that are Not Represented in the Game, and Limits Himselft to Chinese Geographic Space, considering About the Military Strategy of VI Century BC to IV Century BC in the Ancient China, divided by Many Principates, constantly Suffering the Dangers of War, reading Sun Tzu is a very Intesrting and Positive Experience.
Sun Tzu is himself, a defensor of Fast Wars, and to always avoid Besieging Cities, knowing that a Long-Duration War always has more Dangers and Disadvantages than any Advantages it may Cause.

- Genghis.Khan

 

[Hambil]

Keep in mind that the AI will just sit in place if it is damaged and has (or thinks it has) a positive healing rate. I believe this is why barbs will press on in their attack when injured, but other AI players usually won't (though sometimes they will). Leads to some stupidities like a CS unit sitting in one place while slowly being killed by a ranged barb unit. Or worse, an AI force that should be overwhelming getting methodically trashed by the human player because they are all sitting around waiting to heal. It may be best here to take away all natural healing (so the AI doesn't consider it) and then give back hp through Lua only.

I want to just get to the point where we can see how they are handling it. I'd be thrilled to have that much content completed. Then I'll be looking at tweaking the AI. For one thing, it will be easier to see what it's doing wrong.

 

[whoward69]

There is an (unused but operative) TurnDamage value for features - if you just want to see how the AI handles damage from terrain/features, set forest and desert (say) to 10 hp per turn and watch how the AI crosses them

 

[Hambil]

There is an (unused but operative) TurnDamage value for features - if you just want to see how the AI handles damage from terrain/features, set forest and desert (say) to 10 hp per turn and watch how the AI crosses them

That sounds very handy! I wonder if I can put it to use in the mod? However, I don't like relying on undocumented features in releases, as they might go away without notice. But for testing, that willl really help.

 

[Hambil]

I am going to start consolidating things into the first post, so they don't get lost in the thread. I'll use spoiler tags.

 

[whoward69]

I don't like relying on undocumented features in releases, as they might go away without notice.

Well several documented features have changed/gone away in the past, so I wouldn't worry too much about undocumented ones (any way ... what documentation!?!?!)

 

[Hambil]

Well several documented features have changed/gone away in the past, so I wouldn't worry too much about undocumented ones (any way ... what documentation!?!?!)

Good point!

 

[daviiadams]

This has given me an idea to try out that might come in handy for tagging to this

 

[Hambil]

This has given me an idea to try out that might come in handy for tagging to this

I welcome contributors of any and all kinds!

 

[daviiadams]

It's been a while since I've done anything with units, but given the context of what you're doing, how about a supply unit, that works similar to how a great general does? Units within their scope suffer attrition at a reduced rate, maybe even give them an improvement to build (field hospital?)

Make them a high attack priority, so that they are targetted by enemies and I'd have thought the great general AI strategy would work in order for the AI to make use of them.

Maybe hijack the medic promotions?

 

[Hambil]

I have thought about a supply unit, but couldn't decided yet what to do with it. I think it makes sense for great generals themselves to reduce attrition, so a supply unit would have to be a lesser reduction (not being a great person). But we could have an entire promotion path of supply units like CSD does for diplomacy units. I want to keep with the idea of supply coming from friendly cities, so perhaps a supply unit, along with reducing a small amount of attrition, extends the range to search for a friendly city that might have a supply depot built?

Being able to build a field hospital is a neat idea, too, if we can do it in unowned territory. It should probably 'use up' the supply unit though when they do that. And we'd have to come up with a way for the AI to seek and destroy (pillage) field hospitals near it's territory.

 

[daviiadams]

Ah ok, I was thinking of it in terms of sustaining an advance, which could be some distance from the nearest supply option. I might have a play around with the idea and see what comes happens, although it could just be duplicating the whole medic promotion idea that's there already in the game anyway I guess

 

[Hambil]

Okay, I'm not uploading source code as it seems to be a waste of time. But, I will upon request. I think you all know me well enough though to know that if my attention is finally on this, it's happening. Updates soon.

 

[Zimdictive]

There is an (unused but operative) TurnDamage value for features - if you just want to see how the AI handles damage from terrain/features, set forest and desert (say) to 10 hp per turn and watch how the AI crosses them

Could this feasibly be used to make fallout hurt units that cross through it/end their turn there? Though I suppose this would require some addition to the AI so that they considered the cost of creating contaminated land they might have to cross through in their decision to use nuclear weapons in the first place (or, at least, something that emulated the effect of this - i.e. "how near is the target tile to my territory?"+"how much do I covet that land?") rather than just in their consideration to cross it - it would be supremely dumb (and utterly fitting for the AI) to nuke a swathe of land right outside their borders and then set about finding a path around it to continue their invasion on the other side.

 

[Hambil]

Missionaries already deal with attrition in the core game, so I was (perhaps unrealistically) expecting the rest of the AI units to be able to use the same code. But as suggested, I'll test it.