Does anyone else have characters who have the exact same name in their novel? Or have you encountered it in any novel? The only one I can think of is Game of Thrones and it's sequels. In mine, there are two characters called Arthur. I can't change it since both are historical figures.
Not major characters - although I do have some minor characters in flashbacks that all have the same names (my MC's family). Part of the back story is that all the firstborn sons in the family have the name Constantine Joseph Constantinos - the MC's grandfather is Constantine Sr., her father is Constantine Jr., her brother is Constantine III, and her toddler nephew is Constantine IV. But they all go by nicknames (Connie, Gus, C.J., and Fourby) so it doesn't create an issue. I'm not doing it yet but if I ever get a to a future book I'm planning to have my villain's non-villainous niece have the same name and redeem her aunt (they're both named Priscilla - aunt goes by Prissy or Priscilla, niece goes by Silla).
I typically try to avoid it just to prevent things from being needlessly confusing. There's the train of thought that it happens in real life (I know two girls who are best friends and have the same name, hilariously), so it shouldn't be avoided in fiction, and I can get that. It works out fine in real life - someone goes by Kris, one goes by Kristy, one goes by Kristal, or their friends call them by their respective last names or one has an unrelated nickname. So in theory it should be fine in fiction, and is definitely justified. I do actually have an Annia and Annika, but yeah, one goes by Annie and the other Niki. And an actual Annie in another project. I may really like that name or something.
Yeah, Sort of. I have one main character named Reyna and a side character named Zeyna....... Yeah didn't think that through.
If you don't mind changing the spelling, I think Reyna and Zaina or Raina and Zeyna would clear up all confusion. About as much as having two characters called Ron and John.
Usually I avoid it, but I'm liable to do it if it makes sense as an actual topic in-story, or just highlights a similarity or distinction between two characters. I could also do it if one of the characters was named after the other, particularly if they're related (although I don't tend to go for "X Y, Sr." and "X Y, Jr."-type names). And, of course if the characters are someone else's or historical or current real people. I've done this twice that I can think of (or, at least, twice where it wasn't for any of the reasons delineated above). That name is "Brian" both times. Coincidence? Not really, probably. I think most people have a few go-to names that we use when we have to come up with some, and Brian's definitely one of mine (which also include Mark, Jonathan, James, Jennifer, Amy, Mary and Sue). I haven't finished either story yet, though, so I may end up changing some of the names (and I know one of the Brians will at best merely be mentioned anyway).
In the story I'm currently writing, there are two people named Joe. There's the main character and someone in his class. I just did this because I know so many people with my name, so I did the same with Joe. To show it is someone different, the other Joe is called Joseph.