Manga Vs. Anime Question

This is assuming the manga is the source material, of course. If a rule or explanation for the characters situation/powers is stated in the manga but not covered or covered clearly in the anime, can the anime be assumed to have its own set of rules/explanations? This is barring the anime deliberately doing or stating something different, like angelic feathers being actual feathers in the manga, but sharp blades in the anime. I had always assumed that if it is unstated in the anime, then whatever the manga does say is the final word, but I've heard that challenged of late on the series wiki I frequent. Any guidance?

A work should of course stand alone. However, absent direct contradiction, I think it's reasonable for people to use secondary materials to fill in the gaps. However, you should never expect anyone else to use those same materials to fill those same gaps. Interpretation is a personal thing. If having unfilled gaps harms the story or characters, then that is a real flaw of the adaptation.

Unless changed, I would assume the source material would take precedence. Why would you assume otherwise? Not sure why it would be different for anime adapted from manga vs anime adapted from anything else.

It seems like there is a specific question behind this, so it might be easier to just ask rather than doing it this way.

I generally assume anything stated in one canon that isn't contradicted by the other applies to both, irrespective of which came first.

It was specific to a series, but that series has a thread, and I wanted to see what the general idea on manga/anime might be, and the assumption seems to be what I thought, at least so far.

I think it's pretty obvious by now that anime adaptations will shorten explanations to fit and that you go to the source material if you want to fully understand something. Unless an anime adaptation decides to contradict the source, it's pretty save to assume that the reasoning for everything is the same as in the source material, just without telling you the reasoning.

There is literally no reason to assume otherwise.

Normally, I never would. But the people involved advocating this idea to me were not your usual troll or like that. They just insisted (beyond just personal opinion) that if the anime version didn't say it outright, then explanations other than those provided in the manga were in play. Thank you all. I knew pretty much going in what this might be, but didn't want to shrug off some interesting but IMO wrong-headed opinions without asking around a bit. The opinions involve spoilers for the series in question, and they are very series-specific, so I won't bring them up here. Again, thank you.

It really differs based on the series. Many series are specifically animated adaptations (or drawn if the anime was first) of the same canon, while others change some details.

If there's nothing that points towards something having a different explanation, it's likely the same. Doesn't mean it actually does have the same explanation, though. I'd file it under "safe to assume until further notice". But you can't claim it definitely is so and everything else is wrong without evidence from the same work, or a statement that the different adaptations are the same. As long as it's open for interpretation, it's open for interpretation.