Feature Request: Support for Civ4-like non-permanent civics

[PLynx01]

Before creating

• This is NOT a gameplay feature from Civ VI, BNW, or outside - see Roadmap
• This is NOT a gameplay feature from Vanilla Civ V or from G&K - If so, it should be a comment in Missing features from Civ V - G&K #4697

Problem Description

The Civ IV mod currently lacks the non-permanent civics present in the original Civ 4. Making the policy categories for non-permanent policies is a relatively easy task. It requires the cancellation of other policies from the same category after adopting one.

The biggest problem is the AI support for these mechanic.

Related Issue Links

No response

Desired Solution

I would like to add a new Policies.json attribute. The Policy Type.

The allowed values would be:
"Civ5" (Default value)
"Civ4" (Denotes Civ4-like non-permanent radio button policy branch)
"Civ6" (Denotes the Civ6-like idea tree)

The Civ4 policies must be accompanied with upkeep costs and AI priorities.

The Civ6 idea tree must contain AI priorities for each element. The governments and policy cards can be implemented as buildings.

Alternative Approaches

Make a separate ruleset .json files for Civ4 and Civ6-like policies.

Additional Context

For mods based on classic Civilization games, which used the government systems, Civ4 system can be used.

[yairm210]

This should all be done with uniques.
AI priority for policies should be independent of the type of policy, and that can certainly be modified by personality

[PLynx01]

This should all be done with uniques. AI priority for policies should be independent of the type of policy, and that can certainly be modified by personality

What do you exactly have on your mind?
Radio Button Policies can be done this way:

Remove [Government branch]
Adopt [Universal Suffrage]

What about AI priorities? Can you write some pseudocode to explain me your idea?

[yairm210]

I'm saying that "policy type" doesn't help us at all, and is unnecessary, and if we want special treatment it should be behind a unique

What's really needed is AI value judgement which is independent of "what type of unique"

[PLynx01]

I'm saying that "policy type" doesn't help us at all, and is unnecessary, and if we want special treatment it should be behind a unique

What's really needed is AI value judgement which is independent of "what type of unique"

The "Policy Type" attribute applies to policy branches, not individual policies.

[yairm210]

So what? Policy branches also have uniques, same thing
We need to think in terms of what functionality things have, not in terms of what game is this similar to
Maybe Civ IV is comprised of several different things, and so is VI? Then we can mix and match elements

[PLynx01]

So what? Policy branches also have uniques, same thing

So, in that case, can I mark a policy branch as exclusive (or radio button), either using attribute or unique?

That would be useful for making Civ4-like civics, or a single government selection, like in Civ 1, 2 and 3

[PLynx01]

@yairm210 @SomeTroglodyte

Can I try to implement this by myself?

I need to alter Policy Manager and Next Turn automation.

[SomeTroglodyte]

How about this mod:

Policies.json

[
    {
        "name": "Governments",
        "era": "Ancient era",
        "priorities": {
            "Neutral": 5,
            "Cultural": 0,
            "Diplomatic": 10,
            "Domination": 5,
            "Scientific": 5
        },
        "uniques": [
            "Comment [Only one can be active, choosing another removes the previous one.]"
        ],
        "policies": [
            {
                "name": "Despotism!",
                "uniques": [
                    "Remove [Feudalism!] and refund [90]% of its cost <hidden from users>",
                    "Remove [Republic!] and refund [90]% of its cost <hidden from users>",
                    "Remove [Democracy!] and refund [90]% of its cost <hidden from users>",
                    "[+12 Gold] [in capital]"
                ],
                "row": 1,
                "column": 2
            },
            {
                "name": "Feudalism!",
                "uniques": [
                    "Remove [Despotism!] and refund [90]% of its cost <hidden from users>",
                    "Remove [Republic!] and refund [90]% of its cost <hidden from users>",
                    "Remove [Democracy!] and refund [90]% of its cost <hidden from users>",
                    "[-1 Happiness]",
                    "[+1 Production] [in all cities]"
                ],
                "row": 1,
                "column": 4
            },
            {
                "name": "Republic!",
                "uniques": [
                    "Remove [Despotism!] and refund [90]% of its cost <hidden from users>",
                    "Remove [Feudalism!] and refund [90]% of its cost <hidden from users>",
                    "Remove [Democracy!] and refund [90]% of its cost <hidden from users>",
                    "[+20]% Strength decreasing with distance from the capital",
                ],
                "row": 2,
                "column": 2
            },
            {
                "name": "Democracy!",
                "uniques": [
                    "Remove [Despotism!] and refund [90]% of its cost <hidden from users>",
                    "Remove [Feudalism!] and refund [90]% of its cost <hidden from users>",
                    "Remove [Republic!] and refund [90]% of its cost <hidden from users>",
                    "[+2 Happiness]",
                    "[+1 Science] [in all cities]"
                ],
                "row": 2,
                "column": 4
            },
            {
                "name": "Governments Complete",
                "uniques": [
                    "Will not be displayed in Civilopedia",
                ]
            }
        ]
    },
]

...what would that be missing to behave like you want? Then go step by step...

[PLynx01]

@SomeTroglodyte

These are my suggestions:

1. The policy branch should have an attribute or unique, denoting that only one policy can be active at the same time. This would eliminate the need for writing the uniques removing other policies than the adopted one.
2. We need to provide each policy additional info about the AI priorities. That would enable AI to choose policies that reflect their values and ideology. For example, peaceful leaders will more often choose democratic governments when possible, whereas more militant ones will opt for dictatorship instead.
3. We need to specify the policy maintenance costs, which must be taken into consideration by AI, when evaluating the policy options.
4. It's also necessary to specify the prerequisites for adopting the policy. It can be a technology, built building, other policy or any other conditionals, including countables.

I think that's all I want to say for now.

[yairm210]

3 sounds like "[-1 Gold]" unique on policy
4 sounds like "only available when"
2 sounds like a generally useful unique, "[relativeAmount] weight for AI, modified by [personality] personality" - @tuvus is the expert here

[SomeTroglodyte]

eliminate the need for writing the uniques removing other policies than the adopted one

Yes but as you say that's convenience and prettier, so optional and can come later.

That (actually playable) demo mod up there does show some more points, however:

• When are you supposed to be able to begin switching governments? <only available when> is one thing, but culture cost another. That would need some override to behave like older Civs AFAIR - I think they were 0 culture cost and only tech prereqs?.
• What should it cost you to switch governments? Nothing, unlimited per turn? Possibly, no additional feature needed (those 90% in the demo were just for kicks to see it in action).
• BUT - only one change per turn allowed and none of the policies apply (or another set of maluses applies) for the next N turns, as in older Civs? New. I believe that was a thing - wanna change from Communism to Democracy? A few turns of Revolution... Could get tricky to implement.

So - again - go for it, small steps sticking as close as possible to the Uniques system. Once we see it works but could use prettifying/optimizing, that's later PR's.

[PLynx01]

3 sounds like "[-1 Gold]" unique on policy 4 sounds like "only available when" 2 sounds like a generally useful unique, "[relativeAmount] weight for AI, modified by [personality] personality" - @tuvus is the expert here

My remarks:

• Civic upkeep is not fixed, but dependent on number of cities, units, improvements, buildings, population etc.
• AI priorities should be obviously linked to Personalities. But should they be defined by modders themselves or evaluated automatically? I believe the former should be recommended, and the latter should be a fallback.