What about the latter civic trees? Are they still similar to vanilla?
A very important point is that you don't need the medieval era to unlock medieval era policy trees. Once you have finished an ancient era tree (or take any 6 policies, but that not advised), you can immediatly start a medieval tree. And once the medieval tree is finished, you can immediatly start a Industrial era tree. (and then you unlock ideologies automatically).
Ancient era:
1) Tradition -> if you don't have space (or don't want) to expand. It is probably the most difficult tree to play correctly.
2) Progress -> if you have space to expand peacefully. It is probably the easiest tree to play correctly.
3) Authority -> if you need non peacefull way to expand.
Medieval era:
1) Fealty -> Help your religion. But its not relevant if you found or if you are converted. Also help with big empires. Progress/Authority -> Fealty is the "default choice".
2) Statecraft -> Very good if you have few City-States nearby, even if you don't aim at the Diplo Victory.
3) Artistry -> Good for culture and tourism. Tradition -> Artistry is a quite standard choice for culture victory.
Industrial era:
1) Industry -> Probably the default tree. It gives money, and you always need more money.
2) Imperialism -> For expansionist peoples, or anybody on naval heavy maps.
3) Rationnalism -> Don't take this tree if you have happiness problems. It gives you more growth (so more unhappiness), and some of its bonuses ask for your empire to be happy... But if you have the happiness to sustain it, it is a very good tree.
Note that compared to vanilla, culture is as powerfull as science, except that it is easier to catch up in science than catch up in culture, so culture is better in early game.
