First of all, thank you very much for the answers!

I am going to illustrate my doubts with my great photoshop skill (graphic design it's my passion) to ask in a more “direct” way what we are talking about.

First we explain the encounter. At the end of the BOSS 1 there is a secret chest that we will NOT open. We enter through the portal, it takes us to BOSS 2 and... Oh no! We have forgotten the chest. So we want to go back but it is impossible. So, the previous area is designated as an "Area where the developer does not want you to go." This is how I understand it both as a gamer and as a videogame developer that I am. I agree with @oddtom in his first post.

The normal way to get back is to abuse jumping mechanics to avoid the pit. But we are going to propose two different cases:

Case 1: Instead of a huge pit, what appears is a huge wall. We use a glitch to get through the wall. To make it more fair, the glitch is “running a lot and hitting the wall doesn't kill you, it goes through it”. That way we get to the secret chest that is in an area where the developer does not want us to go. We all agree that it is OOB.

Case 2: No pit or wall appears. But when you're jumping forward a message appears that says "Return to the battlefield" and a 3-second timer force us to return. To cross the abyss we need at least 10 seconds. It is impossible. But then we use the same glitch as in case 1, super speed. And we cross the abyss, we are off limits in an area where the developer does not want us to go. The difference is that we have crossed a PHYSICAL wall or an INVISIBLE barrier. But the result is the same.... Is this OOB?

In case the question to case 2 is negative (That is, it is not OOB) ... What kind of glitch is it? What required conditions must a glitch have to be consider as an “OOB”?

This is my first topic on the forum and I hope I am in the right place. I am a huge fan of what all the people here are doing!

I have recently started making videos about Destiny 2 and I want to make one focused on the OOB, in this game it is very common to use glitchs to go out of the map and complete speedruns. Even some mechanics of final bosses are made thanks to OOB (The 99% of the players who use it do not know what it is called or what it consists of. They just do it).

So, to start the video I want to correctly define "What is the OOB" what it consists of and if it has different variables and/or rules. And that is why I come to all of you. I would like to know where I can find out in full detail what the mechanics consist of and what "rules" it is subject to.

I'm going to put an example of my doubt. During a raid (Last Wish) you can backtrack and reach an area where you have already been. This skip is used to farm a chest that you should not reach. I will attach a video to show it. My question is... Could that be interpreted as an OOB? Although you have not used a glitch, you have jumped a natural barrier created by the developers to reach an area where you should not be. What's more, you must go a very specific path or the death zones will kill you.

How far can we say that that is OOB or Skip? How can I know and define it? What rules does the OOB have? Should a glitch always be used? You must always literally "get out of the map" thanks to some mechanics or glich?, or is avoiding a "joining allies" barrier also an OBB?

Thank you very much for your time!

The video: