She has a 50% chance to dodge in the impossible difficulty, though there are also some special rules to prevent being very lucky or very unlucky:
-She can't dodge twice in a row, so if she already dodged once, the next attack will surely hit her;
-She can't be hit three times in a row, if you hit her twice in a row, she'll surely dodge the third attack.
For the normal mode these special rules are different.
Edit: Also she won't dodge after the final attack.
If you mean I can't hit Undyne three times in a row I've made it several times, she also dodges very often, sometimes even twice in a row idk if it is a bug or anything else
No, it's not a bug, in normal mode Undyne can dodge twice in a row, but the chances to dodge your attack are 20%, also you can hit her three times in a row.
What I said in the previous comment is only in the impossible mode.
I know, the things I said happened to me in the impossible mode, that is the reason I asked if it was a bug or something like that, I even recorded in a video the three hits in a row thing, but I can't share it because it is too heavy to share it here
Yeah, I checked the code for those special rules, and there's actually a ">" instead of a ">=" in the part where it checks for the hits in a row, so right now you can hit her three times in a row in impossible mode and four in normal mode, thanks for making me notice this bug.
The part with the number of dodges seems right though, she can dodge only once in a row in impossible and twice in normal.
