Going off track to the DM's narrative to garner experience and potential loot isn't abusive to the GM? It would require the DM to do quite a few things. 1). The DM could Force his narrative thus potentially aggravating his player characters. 2). Force the DM to design things on the fly because he wants his world to have a semblance of realism by perhaps saying. "Yes.. you sense a den of kobolds about 5 miles east of here." 3). Remove this ability by redesigning or crafting encounters solely to limit the use of this ability.
No, I don't think it's "abusive to the DM." I don't know what you mean by #1. For #2, in my opinion this goes back to the players and DM being on the same page with regard to how the game is played. For #3, I don't think that's necessary, but it's not uncommon for DMs to create challenges that allow some class features to shine whereas others do not. Many class features are fairly situational anyway.
Can any other class claim this power over the DM's creativity?
Can any other class claim such an ability which is virtually on at all times since game time takes no real time when traveling etc. (DM, I would like to check for favored enemies every 2 miles we travel). Of all the classes across 5e, I don't know of any ability which has such information gathering capability.
I don't see why any of that matters to either the DM or the other players. I certainly don't see the players' chosen class features as some kind of power struggle with my creativity as DM. It just enhances it, really, as it should do.
Does a DM also have to design his challenges with the Ranger's ability in mind? What other class can force the DM to do such a thing?
All of them? As I say above, many DMs create challenges specific to the strengths and weaknesses of their party. Or build challenges suitable to their players' level of skill with the game (e.g. a veteran player might need higher difficulty than baseline to be satisfied with the challenge).
And you don't see how this can be abused to give the players a much greater advantage than I feel is the intent of it's purpose? Heaven forbid you have rogue multi-class as a ranger just so he can choose this ability at lvl 3 for humanoids. This would make him the greatest spy/thief/assassin in the know 5e world. How would a DM deal with a player with 8 or 9 levels of rogue and 3 levels of Unearthed Ranger who decided they wanted to use this ability to keep track of the movement of guards in a castle, or a an enemy lair, or any other place in which their favored enemy resides? "DM I would like to spend the next 4 hours tracking the movement of all favored enemies."
Okay, you know the location and type of the favored enemies. What do you DO with that information? That's what is important in my view. I don't care if the players have that information at all. And in any case, they won't have the location and type of enemies who are
not favored. The ranger won't detect the mastiffs that accompany the guards or the vampires in the castle's crypt or whatever. It's imperfect information.
And you don't feel this ability can be abused? I agree that the DM has the ability to resolve this, but in doing so his options are quite limited. Either he can design and build a world in which there are few, if any, of the rangers favored enemy thus crippling the class in a large way. Or he can make a house rule.. something that shouldn't be required, or he can just keep killing of players who are creative and can see how this ability could be used in a variety of ways to benefit the party and frustrate the DM.
Who is this DM that gets frustrated when the party gains an edge in the game? And what game is it that this ability will always give the ranger the edge? It doesn't seem very likely to me.
Can we open a dialogue about how my proposal wouldn't solve the problem?
If you limit this to a number of times per long rest (Wisdom modifier perhaps) you remove a great deal of abusive potential by forcing the Ranger to make a decision about WHEN this should be used. If you can't use it limitless times, you must make a judgement call on when to use this ability. Do you waste it when there could be, potentially, none of your favored enemies nearby? Do you save it until your other skills have brought you close enough to have a good chance of finding what you are looking for? Do you use this before entering a lair in which you know there are favored enemies to get a good idea of what you are facing or do you save it for after a large encounter in which you can provide a way to track potentially fleeing enemies or ensure the safety of a battered team? I don't see how limiting this ability is a bad thing or won't solve the problems. Please speak to that point as you have challenged that this ability isn't able to be abused when it clearly can be.
I challenge you to find any class with any similar ability which is constantly available to them which can provide such information over a broad range with no limitation on uses or costs to the player.
I have no issue with limiting the ability to create more of a meaningful decision point and fun trade-off for the player. That's something at least and maybe your proposed solution solves THAT problem. But if your complaints are about it being abused as it is currently written, then I would say (1) I disagree that your examples are demonstrative of actual abuse (but
are demonstrative of some deeper issue with the game that this ability reveals) and therefore (2) your proposed solution does not achieve your goal of eliminating what you perceive as abuse.
This is not a DM problem. This is a design problem. Any ability which can force the DM to behave in a way that limits or requires them to build, design, GM or constantly be aware of that ability in the course of their game is both abusive to the DM and abusive to the other players (why bother having a rogue when you can just tell the mage and BSF what is behind the door because you spent 1 minute tracking your favored enemies). Pretty soon you will just have a party of Unearthed Rangers running around all with different favored enemies so that they can never be surprised and can always know what the DM has ready for them.
I'd love to DM a campaign like that. Because to me it's not always about what you know. It's what you DO. That's where the interesting stuff is found in my view. Players knowing things just mean they get to DO more stuff. That's fine by me!
If you're interested, I've written
several actual play reports focused on how the UA revised ranger did. I think you'll find that Primeval Awareness is just not as big a deal as you think it is.
Edit: I reread what I linked and only one report saw a ranger use Primeval Awareness. Two PCs in different games had access to it, but only one actually used it.