This is another topic that keeps cropping up that I might collate into a megathread.
I’d echo what Silver/ says, and that my experience with my Oath of Devotion paladin was actually a lack of meaningful oath breaking opportunities and I think I already listed in another thread a variety of stuff my paladin did that I felt should have affected his oath but didn’t. True, there are some cases where specific actions (such as executing murderous goblins or opening a prison cage door to inspect the body of a goblin raider) break the oath incorrectly in my view. I hope Larian will have more sophisticated treatment of killing “neutrals” and “thieving” in the full release that will manage this better. In the meantime, oathbreaking can easily be avoided by having a party member do anything vaguely dodgy, and this will not affect the paladin’s oath.
Regarding other subclasses, I confess I did wonder whether Larian didn’t implement the PHB Oath of Vengeance paladin for players in EA partly in order to test player demand for it when the Oathbreaker is already available (as well as, no doubt, to get more folk testing oathbreaking). My view is that we do need that option for more morally grey, or downright evil, paladins as well, and I hope it will be there in full release.
I also hope that the full release will be more explicit about the nature of the oaths our paladins swear, and at least set out the basic tenets of each in game, even if they also say (as I think the rules do) that the actual oaths paladins swear may vary.
And with respect to mending a broken oath, I agree that high expectations for custom content are probably not reasonable. According to the rules, I think atoning for a broken oath might include something like a vigil so I generally just headcanon that this is what my paladin is doing. Though that might actually be a nice and relatively easy addition to the game: we hand over our gold but nothing happens until the next long rest, when rather than seeing our paladin sleeping we see them kneeling with head bowed in contemplation then surrounded by light to signify the mended oath, or something like that.
A slightly more complicated version that still seems doable, might have the Oathbreaker Knight come to our camp the first time we break our oath, but for subsequent occasions (once world map travel is available) tell us of a specific location we need to go to in order to find him and become an oathbreaker proper, or redeem our oath. And perhaps also give us the option of approaching priests at some temples and handing over our gold to them rather than the Oathbreaker Knight. I also think each broken oath should become more expensive.
