Pact-making 101: A guide to the 5th edition Warlock

[MaxWilson]

If the enemy is within a 20ft radius.
In my experience, your party members are much more likely to be inside that radius than enemies-if you go off away from the party and do this, the enemies will more than likely ignore the darkness bubble and go after the party, while you don't get advantage on enemies OUTSIDE the darkness. It's also a concentration spell, so getting hit has a decent chance of disrupting the spell, and you can't concentrate on, say, hex for increased damage output. It's good, I don't see it as being broken, or even necessarily worth the invocation.

that being said, if your whole party are warlocks/dipping warlock to do this trick, it's pretty damn awesome.

I think you mean "120 ft", not "20 ft". Was that a typo?

Here's how it works:

Devil's Sight lets you see through magical or non-magical darkness up to 120'. You cast Darkness on yourself or something you are wearing, which provides magical darkness within 15' of you. Now, nobody without blindsense/Devil's Sight can see you, so per the visibility rules all your attacks on them are made with advantage unless they have the Alert feat. Likewise, because they cannot see you, their attacks on you are made with disadvantage. Your fellow party members shouldn't be within 15' of you or else they will take advantage + disadvantage on all their attacks (which cancels out but is annoying and probably needs better rules), so your Darkness isn't impairing them at all.

If you attack creatures more than 120' away you take advantage + disadvantage as normal for zero net effect.

I agree that Devil's Sight is not the first invocation I would take (there are other ways to get advantage), but if you do happen to have it you should exploit it for all it's worth.

I'm curious which racial traits you're referring to here-I don't see many which I wouldn't trade for a feat.
The argument I've heard made is that some characters with 1st level feats trivialize certain types of enemies and encounters. Heavy armor master on a fighter or paladin, for instance, makes them mostly immune to goblins, kobolds, etc.

While I agree with your overall point, I disagree with the particular example. Heavy Armor Master on ONE character doesn't trivialize encounters with kobolds because they can just target the squishiest character (and they're smart enough to do so). Heavy Armor Master doesn't have to personally worry about dying to kobolds, probably, but the encounter isn't trivialized because he still has interesting choices to make.

There's nothing wrong with trivialized encounters anyway. You don't even have to play them all out.

DM: While on the road to deliver your important message to the king, you [heavily-optimized high-level character] stumble across an orc guarding a pie.
Player: I kill him and take his pie and eat it.
DM: You eat the pie and continue on your way, leaving behind the corpse of the orc.

You didn't have to roll for initiative or damage or anything--it's obvious that the PC kills the orc with no significant losses to himself, and rolling dice would just be masochism. That doesn't mean the encounter wasn't interesting though, and it doesn't mean it couldn't have consequences down the road. Or not.

As AngryDM says, encounters always end when the dramatic question is answered. In this case, the dramatic question was not "can PC kill a lone orc?" but rather "how far will PC go in order to get a pie?" We just learned that this PC will murder for pie. That's interesting and non-trivial, even though the "combat" was in fact trivial.