From reading Ontological Inertia I get the impression it allows changes of single events but not of trends. However, that is not how You Can't Fight Fate defines OI.
I thought Ontological Inertia was that if you defeat a villain that used magic or something then the effects of that villain don't disappear unlike No Ontological Inertia
Analysis.Ontological Inertia attempts to lay out a distinction, but my eyes glaze over trying to read it. (Also, for future reference, these sorts of queries can go to the Duplicate Tropes Discussion Thread.)
RJ Savoy
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The titles are misleading, but they have nothing in common.
I think in practice the only difference is that YCFF is about prophecies, and OI about time travel. The same result but arrived at with different means, and in different genres (YCFF is mostly from sword and sorcery fantasy, OI is more in science fiction).
Stories don't tell us monsters exist; we knew that already. They show us that monsters can be trademarked and milked for years.
Captain of USS Bajor
Ontological Inertia should probably get a wick check. It's only 133 wicks.
Lucas the Dreamer
Ontological Inertia is about being unable to change history, even retroactively. You Can't Fight Fate is about a character trying and failing to prevent some prophesied event from occuring.
Why waste time when you can see the last sunset last?
I have this time travel fanfic I'm building a tropes page and it is an exemplary case of the trope You Can't Fight Fate so, I was going to add it but then I found what seemed to be its sister trope: Ontological Inertia. I went to read their pages and the latter was described as a specific case of the former, but for the life of mine I can't figure out the difference between the two of them. The fanfic goes like this. Two canon characters are assassinated (they're the canonically main characters), then some characters go the Peggy Sue route to try and prevent their deaths but no amount of time traveling will ever change the past. The characters have to die and a Burning Legion invasion will have to happen. So, characters can change the way those events happen but not the fact they have to happen. I read carefully both tropes' pages and the situation fits both of them. So I'll add both tropes in the examples section of said fanfic. However, how can I describe them differently? I'm not sure why those two tropes are different, so I'm lost. Some help, please?