falloutttt: You DO need them. Otherwise, the AI will have the options that you don't have. And you'll have many buttons right in your face, that don't work since you don't have the DLC. On top of that, there are bugs (in the DLC-less versions) that they don't fix. In a sense forcing to buy the DLC.
It is going to be moddable. But what's the point in buying a broken moddable game ? heh :D
My advise, is to wait couple of years. That's usually the time it takes for them to fix the main game. (not the bugs that comes with DLC). The bugs that comes with DLC are "hopefully" will be fixed in the future. well, 75% of them more or less.
Kaaedus: Beyond the fact that the AI controls nations that may be locked behind DLC, I've yet to see any blatant examples of the AI taking advantage of any DLC features that the player does not have access to. Furthermore, any discussion that I've read on the subject up until now came to this conclusion as well. I'm curious as to how you arrived at your conclusion.
I also have not seen any modern examples of bug fixes delivered exclusively via DLC. In my experience, DLC is typically accompanied by a free patch that everyone has access to. Sometimes these patches do introduce bugs, but that is why there are typically a few revisions between major releases. There are a few exceptions to this, HoI3 for example did include patches with DLC I believe, but no modern Paradox game has done it this way to my knowledge.
This is not to say that Paradox is a perfect developer/publisher, or that I agree with everything that they do. As you've pointed out, buttons and UI elements that are not functional if you don't own the correct DLC are annoying, for example. Ultimately though, their implementation of games as a service is one of the less offensive that I've come across.
I do agree that it may be advantageous to wait if you're on the fence. Waiting will result in a more stable experience for sure.
I used to buy every DLC and played CKII and EUIV for many years. My two favorite games, actually.
Since about 2 years now I only pirate Paradox games with all the DLC included, therefor I don't know how it plays without certain DLC today. And so i won't argue.
But back in the days, if you din't had a certain DLC, you're in disadvantage. Again, not going to argue cause it's pointless anyway.
The reason for pirating is that i don't want to support paradox anymore. They are greedy and very nasty bunch of people.
By buying DLC and supporting Paradox, we(me included) created all this greediness. Witch is why the games they release today are half-games, totally broken, especially if you're planning on playing the game to the end. And instead of fixing bugs, they release new DLC that comes with new bugs. And to this day, with all the money they make, they still don't test their products before release.
In the end, as much as i love this type of games, it's not worth supporting this dickheads. Cause nothing is going to change. They love making their money, and they really don't give a flying cow on what anyone has to say about the quality of their product or anything whatsoever. They are here to make money! When back in the days, they actually cared about their games, their customers and made wonderful games like "Knights of Honor".
That's all i'm going to say. :)