Ranger with Outsider favorite enemy goes plane travelling. How does his bonus work?

[Hua]

If he is the one that goes to another plane, the locals are natives, as far as they are concerned.
To the ranger, are they still considered Outsiders? Does he still get his favored enemy bonus against them (assuming sub-type is correct)?

[Wildstag]

An Outsider only has the (Native) subtype if it is from a Prime Material Plane. The Outsider type is a creature made of a less-than-real plane. The (Native) subtype is not the same as the (Extraplanar) subtype. The latter is for any creature not on its home plane. A tanar'ri on the Abyss would still have its (Chaotic) and (Evil) subtypes, so if the ranger has Outsider (Evil), they would still get the full use of the bonus on that plane. If they went to The Outlands and fought a Tanar'ri it would still have its (Chaotic) and (Evil) subtypes, but also would have the (Extraplanar). The Ranger would still have that bonus to damage when fighting an Outsider (Evil), even though neither is on their home plane.

[holbita]

Outsider is a type. it doesn't matter where you are... you are still an outsider. You have examples of such thing with the planetouched races. If you have Evil Outsider and you find an evil tiefling... you get the bonus. Doesn't matter where you are.

[Tzardok]

Favoured Enemy: Outsider (Evil) doesn't apply against tieflings, no matter what alignment they have. The ability only cares about what subtypes the Outsider has, and tieflings have the Native subtype, not the Evil subtype.

Incidentally, questions like this are the reason why I renamed the Native subtype in my houserules. I call it the Visceral subtype (because these outsiders have actual flesh-and-blood bodies and aren't just made of solid planar essence pretending to be living organisms).

[holbita]

My bad.

Yes, evil tiefling in this case is a tiefling with the evil subtype, they don't normally have it but no native outsider with an alignment subtype came to mind when I was writing my reply... I could definitely have phrased it better though.

Good point.

[Powerdork]

Yes, it's worth thinking of the native subtype as a variant of the normal Outsider type, and like Dragon and Magical Beast and Elemental and evil and cold and gnoll, a type does not represent the circumstance you find yourself in, it represents what kind of thing you are.

The one exception is that the extraplanar subtype is a conditional subtype that applies to most any creature not on its home plane, regardless of circumstance. (It'd probably be better rendered as a condition than a subtype, because of how easy it is to gain and lose and how few things it helps qualify for.)

Outsiders are typically made of the matter of the Outer Planes, those aligned worlds that sit at the rim of the transitory Astral Plane. They're formed from belief and concepts, and only when that ceases to be true do they stop being Outsiders. (Such as if a template turns them into a Dragon or a Construct, for instance.)