I see... You thought the Moai improvement will behave like the Polynesian's unique improvement in V. It was a Culture improvement that needed to be adjacent to Coast. Both gain additional Culture per adjacent Moai.
VI' Moai has no longer that requirement, but do enjoy +1 Culture if it adjacent to a Coast or Lake. The requirements are both being on Plains/Grassland (no Desert, Tundra or Snow)*, and not adjacent to Woods/Rainforest. It has an exception: they are allowed on Volcanic Soil, and gain +2 Culture on it.
They are very potent Culture, therefore Tourism, generators.
Here something from me:
- You can attack religious units inside a City-Center if you are at war with them. When you defeat the enemy religious unit, you don't go inside the enemy City-Center.
- Your 3-promotions Spies can level up one more time with the Terracota Army. It even allows to pick a 4th promotion. Sadly it doesn't work for Rock Bands, which cannot go to level 5 (level 4 didn't have Promotion anyway).
- It is possible to get reliably a Builder with 9 charges, and many with 8. It is achievable when you unlock Civil Engineering during the turn. It allows to slot both "+2 charges" cards for the current turn. Pyramids and Liang allows to get to 8 and 9 respectively. Qin Shi Huandi (Mandate of Heaven) can get 9 and 10 charges builder instead.
- Mausoleum at Halicarnassus' additional charge on Great Engineer is dynamic. It would increase when built or conquered even the charge of already recruited Great Engineer. It would also decrease when lost (conquered, rising sea). That way, it is possible to have Great Engineer with 0 charge (so worthless) if you use all but 1 charge, then lose the ownership of wonder.
- Siphoning Gold with Spies is made weaker when they takes less times to do the mission. It is because they are stealing the GPT of the city for the duration of the turn. If you have -100% on Spies, then you will Siphon 0 gold as it is 0 turns of GPT.
- It is possible to put a Château on a Floodplains, even if there is no adjacent resources.