Hello. I am a beginner player and I would like to find out which DLC's are the most important and which are not. I want to know in what order I have to buy DLC's (from the most important to the least important) Thanks! (sorry for bad English)
I'll give you my list from most important to least important; and split them into tiers of importance as well:
Top Tier - Must-have; Paradox should honestly sell a bundle with Base Game+these
1: Art of War - Pretty much any form of vassal play basically needs this DLC. Transfer Occupation is a godsend. League War is nice; and extra revolution mechanics is good too.
2: Common Sense - Basically required to play in RotW now; especially Asia; unless you WANT to be eating 100~150% tech cost maluses. There's also the fact that as monarch points have become more plentiful [Usually via there being more money in the game; and thus you can afford better advisors] you actually can find yourself with too many monarch points. Development lets you invest your points into making your nation richer and stronger.
Oh; and Constitutional Monarchy is good [Albeit; Absolutism makes it RP-only these days]; Theocracies are a brilliant gov.type with the DLC; Protestant+Buddhist mechanics...
Also lets you do National Focus.
High Tier - These DLC's are not game-shattering like the Top 2; but are still very; very good.
3: Cossacks - Estates add an entire other level onto the game's strategy. Every feature in this DLC is pretty good; although not essential. Worth noting that the Horde-based mechanics are slowly becoming less useful; especially with Cradle making Timurids and the Sheep not Hordes. I placed this just outside Top because some people hate the micromanagement of Estates, and if you don't like Estates...
4: Rights of Man - Queens; Disinherting and so on is an absolutely giant buff to any Monarchy. Fetishist and Coptic mechanics make playing in Africa significantly more fun. Subject orders help with vassal play.
5: Cradle of Civilisation: This high purely for the Drilling -> Get more manpower button. Islamic schools are pretty cool; although propagate religion is almost pointless [It's basically just for converting Indonesia.] Iqua mechanics are kinda OP; and the unique gov.types are goof for the Middle East.
Md Tier - These DLC's are more niche or have less content; and you can do without them quite easily.
6: El Dorado - Can be avoided if you don't care about Custom Nations or playing as Andean/Incan/Aztec nations. However; if you enjoy these things; El Dorado is great.
7: Wealth of Nations: Solid; especially for India or Reformed players. But otherwise pretty light.
8: Mare Nostrum - It's a lot lighter on content compared to the above DLC's. But it does impact worldwide.
9: Res Publica - Basically only effects Netherlands and Merchant Republics. Notably; National Focus is in Common Sense as well; drastically lowering the value of this DLC. Res Public is cheap however; especially when on sale!
10: Mandate of Heaven - Actually makes East Asia unfun and you might want to outright turn it off if anywhere near Ming. However; it does contain Golden Ages and Age Objectives; and without these; it would be last place. However you can quite easily live without the Age bonuses/objectives; and it's hard to justify the price tag for just those.
Low Tier - These DLC's are very niche; and give little content outside of said niche.
11: Conquest of Paradise - If you want to play as a Totemist native American; or release a colony and play as them, you need this DLC. Otherwise; you can completely and utterly ignore it.
12: Third Rome - Do you want to play as Russia? Alright. Do you want to play as any other relevant country [Since every other Orthodox country is basically either Muscovy fodder or Ottoman Fodder]? Avoid this like the plague. This is the only DLC with basically no replay value. Also it's quite overpriced for what's in it.