Remathilis
Legend
Well then, IMO you are just plain wrong, because all D20 games are based on 3rd edition, which has very very different core mechanics to 5e.
Example of a core rule in 5e: "In combat you get one action, and may get up to one quick action and reaction." This is core rule of 5e, but is not a rule in any D20 games.
An example of the many core mechanics that are part of D20 which are not part of 5e: "for every 5 points of BAB you get an extra attack at BAB-5". And there are many more regarding multiclassing, skills etc.
If you have played those games (I have) you would be aware that the feel of gameplay is very different.
On the other hand, Pathfinder has pretty much all the same classes and races as D&D 5e - so you are pretty much proving my point - it's not the classes and races that are core, it is the gameplay mechanics.
1. The One Ring is 5e based.
2. You're making a semantic argument; they're all d20 based, use similar concepts (if not perfect executions) and are all based on the same OGL, which doesn't discriminate between 3e and 5e.
You seem to think I'm some noob whose never played D&D before 5e. You're wrong and I feel your ad hominum attacks are not worth further response. Good day.