I’ve beat Divinity: Original Sin 2 twice before playing this game, and that has definitely influenced my experience — but not in the way I expected. I thought I was going to be frustrated by the lack of certain improvements found in the sequel or overall less interested in the world after spending 200 hours in it in the last few years. But it was actually the opposite. Having the benefit of playing the Enhanced Edition many years after the original release date, I found DOS1 to be surprisingly polished and friendly. Almost everything I loved from the sequel was here, albeit different. I even preferred some aspects here, like combat, which is less complex but also less chaotic and more immediate (the armor system of the sequel is a choice). The story also benefited from the narrower focus. It doesn’t have huge twists but it’s intriguing and engaging, with memorable characters and a neat Homestead you can come back to after lengthy quests for a bit of a breather.
Overall, I found DOS1 an essential play for DOS2 fans — not because it’s necessary to understand or enjoy the sequel (it’s actually the opposite), but because it’s just as good. Play it before, after, it doesn’t matter — but play it!