I like your idea Sostratus to make a single city a powerhouse of Tourism by spamming wonder, a little à la City of Light from Civilization V that give bonus to Paris at theming. Your idea is even better because you are not stuck to Paris (because if you have a bad start position with few wonder slot, you are screw). But it also make the civilization fairly easy to deal with: just capture that city, enjoy all the wonder for you, and eliminated a cultural threat. Furthermore:the base Tourism of a wonder is really low, making winning a tourism victory by building wonder is really difficult.
Not a fan to downgrading the Garde Impériale to earlier. I think we need a fix by putting all the unique unit out of unit line to be inside a unit line. Or if you prefer, make Garde Impériale an ealier Infantry that doesn't need oil.
Except for the Château, I think it is better to make general change that will affect all civilizations, but France will enjoy the most.
Culture and Tourism: maybe making that more useful?
In Civilization V, dominating a civilization with your culture have some nice side effet like a Science bonus on trade route, or a chance to flip city to your civilization if near you with an ideology. Maybe we need something in that spirit, and allow Tourism civilization to catch up, like draining Diplomatic Favor, a discount on science for technology already discovered, or a reduce combat strength of enemy units from dominated civilization.
Furthermore: the Wonder are a bad way to achieve a Tourism victory. Having all Ancient (6) and Classical (11) wonders yield 57 Tourism (114 with France) at medieval age. 4 Great Writers give more than that. The base Tourism from Wonders should be increased from 2 to 4.
Unique unit: on the line!
It is simple: all unique unit that are not a replacement can be upgraded from a less advanced unit of the same line and can be upgraded to the earlier unit of the line. For the Garde Impériale: can be upgraded from Musketman and upgrade to Infantry (and not have to wait to Mechanized Infantry).
Some side note: Garde Impériale should not cost Niter to upgrade, or very few, because the Musketman already have it.
Something to think about: should Archer upgrade to Maryannu Horse Archer or Saka Horse Archer? It is the same line of promotion afterall.
Focus on France: le Grand Tour des Châteaux!
One funny thing about France is that the bonus Production don't work for the Eiffel Tower, because it is a Modern Era wonder, but Grand Tour stop at Industrial. As era pass, the number of wonder of wonder available decrease: 6 Ancient, 11 Classical, 10 Medieval, 7 Renaissance, 8 Industrial, 4 Modern, and 3 Atomic. It will not be a great change to allow France to have an increased production for 7 more wonders, even if Modern era focus a lot of Tourism.
Château is weak compare to Rapa Nui or Granada UI. We can't make it a fort: it will be to similar to Great Wall or Alcázar. Maybe we need to get more inspired from Cahokia Mount. Like a 1 Culture, 1 Housing, 1 Appeal, 1 Amenity if next to a luxury (multiple Château around a single luxury can only have 1 Amenity), +1 Culture for each adjacent wonder, +1 Culture at Cultural Heritage.
So, in final, I will end by something like that:
Grand Tour
Double Tourism from Wonders of any era.
+5% Production towards Ancient Wonders, increased by 5% for each following era wonders.
Basicly: +5% for Ancient, +10% for Classical, +15% for Medieval, +20% for Renaissance, +25% for Industrial, +30% for Modern, and +35% for Atomic era Wonders.
Garde Impériale
Can be upgraded from Musketman, without costing any Niter.
Upgrade to Infantry, and doesn't have to wait to Mechanized Infantry.
Château
• 1 Culture, 1 Housing, 1 Appeal
• 1 Amenity if next to luxury ressource (multiple Château around a single luxury can only have 1 Amenity)
• 1 Culture per adjacent wonders
• 1 Culture at Cultural Heritage
Tourism from Culture at Flight.
Can only be built on river.
Tourism & Unique Unit change (general for all civilizations):
- Base Tourism of Wonder are now 4 (instead of 2).
- Civilization dominated by Tourism now give extra benefit to the dominant Civilization. If a civilization have a Tourism higher than 25%, 50%, 100% and 200% of domestic tourism of an other civilization, it have those bonuses*:
- 25%: Enemy units have -2 CS against yours
- 50%: Enemy unit have -3 CS against yours, and you enjoy 10% discount on Science for technology discovered by that civilization.
- 100%: Enemy unit have -4 CS against yours, you enjoy 15% discount on Science for technology discovered by that civilization, and you drain 2 diplomatic favor per turn.
- 200%: Enemy unit have -5 CS against yours, you enjoy 20% discount on Science for technology discovered by that civilization, you drain 3 diplomatic favor per turn, and cities of that empire suffer twice as much your loyalty pressure.
- Unique units out that don't replace a unit can now be upgraded from a unit of earlier era. They can by upgraded to the earliest unit of the same line available, but that unique unit become obsolete only at the second earliest unit of the same line available (for example: Garde Impériale now can be ugraded to Infantry but get obsolete when Mechanized Infantry is avalaible). When two units are available (like Crossbowman and Crouching Tiger), the unit upgrade to the unique if it is inside a city-center or an encampment, and to the regular one elsewhere. If the unit need strategic ressource, but the upgrading unit already use that strategic unit, therefore it doesn't need that strategic ressource to upgrade (for example: Musketman doesn't need Niter to upgrade to Garde Impériale, but the Swordsman need Niter).
* : Those values and effects are not definitive. The whole idea is to give player focusing on Tourism to have some catch'up mechanic. I have choose to help those cultural civilization to defend better, catch'up in Science, being a threat in Diplomatic Victory and, in the end, becoming a real pain to contain if a neighbour completely ignore Culture. The value can be changed. Even some catch'up can disappear if not relevant.
Basicly, Tourism victory is now a threat and you have to watch out for your Culture if you don't pursue a Tourism Victory, or your whole civilization can flip while loosing diplomatic access. Furthermore, wonders give more tourism, making France, China and Egypt more useful for a Tourism Victory with wonders, and France have a production boost toward wonders that increase with the era. Now that Musketman upgrade to Garde Impériale without costing any Niter (or costing Niter if from Swordsman), France have an edge to conquer all the continent with ease at Industrial era. The Château is different and allow french cities to grow happier with extra Housing, but will have a little less Culture at the start and overall in exchange. Finally, I propose more change than I thought I will propose.
