I'm a little late to the party on this, but at the beginning of this month, WotC released a new Unearthed Arcana, with subclasses and fighting styles particularly targeted at Underdark campaigns. The good news is, nothing in them requires the Underdark - their conditions just come up more often there. Let's see what they've given us here.
First off, we have two new fighting styles, Close Quarters Shooter and Tunnel Fighter. Close Quarters Shooter is one-third of the Sharpshooter feat plus one-third of the Crossbow Expert feat (the really important part) plus half of the Archery fighting style. Um... wow. It's probably fair to say that other Fighting Styles are about on par with a feat, but this is the first one that feels like a feat because of its many moving parts. There's no question that this is desirable for every ranged weapon wielder, until and unless they spend feats to pick up the rest of Sharpshooter and Crossbow Expert. The other Fighting Styles synergize with feats, rather than overlap. I would hope that DMs keep this in mind and allow players to respend Fighting Styles that no longer have a function. It's interesting that paladins get Close Quarters Shooter as an option, but not Archery.
Minor note: The attack bonus from CQS applies more broadly than the bonus from Archery, because "+2 bonus to attack rolls you make with ranged weapons" requires the weapon to be categorized as Ranged, as compared to "+1 bonus to attack rolls on ranged attacks." Definitions have technical meanings; the Thrown property allows melee weapons to make ranged attacks, but does not make them ranged weapons. Houseruling Archery to apply to thrown weapons won't hurt anyone, though.
Another minor note: If you want to fight with a net, Close Quarters Shooting is a great way to make it viable... since otherwise net attacks always have disadvantage, unless you solve for it with Crossbow Expert.
Tunnel Fighter is also incredibly potent, by tossing out the hard limit on the number of opportunity attacks you might make in a turn. It is absolutely incredible in the hands of a polearm wielder, and outright unbelievable in the hands of a Polearm Master. You're looking at
increased reach from the polearm, which multiplies the effect of
an opportunity attack against every creature that enters your reach, and
spending your reaction to make a melee attack against one creature that moves more than 5 feet while within your reach.
The only constraint here is the increased demand on your bonus actions - you can't both be in defensive stance and attacking with the haft of the polearm, which was previously the more desirable half of Polearm Master's power. Thematically, it seems odd to me for polearms to be the best combination with Tunnel Fighting. My main objection is that polearms didn't need more help. Also, good Lord, this thing is overpowered in combination with the Sentinel feat, because it solves for the one limitation on Sentinel's egregiousness (one opportunity attack per round). It touches on some of the same fighting-style concept as the Protection style, but without the shortcomings of Protection.
Deep Stalker Ranger Archetype
I don’t want to suggest that this Deep Stalker is meant for any particular ranger. Certainly not their #1 headlining Forgotten Realms character. (If, like every non-traitorous citizen of Alpha Complex, you've been reading my Ranger series on Tribality, this commentary is going to look real familiar.)
Underdark Scout is a feature with a lot going on. It does three different things, all of them handy: +10 Speed on the first round of an encounter, a free extra attack if you make an attack on the opening round of an encounter, and a Hide attempt as a bonus action at the end of each turn after the first (rendering Vanish mostly obsolete, unless I misread).
This is immensely dominating skirmishing power. Giving you something else to do with your bonus action is a mixed blessing – the ranger has plenty of options competing for each bonus action. It also reads to me like a sidelong effort to fix what was wrong with the Revised Ranger’s Skirmisher’s Stealth.
Deep Stalker Magic addresses the ranger's tight limitation on Spells Known by granting five more. They’re all pretty good, but greater invisibility is huge. Really, really good move on not granting new spell options without expanding the number of spells known.
Giving Hunters and Beast Masters their own five bonus spells would be fine by me.
Iron Mind is here because the, er, Under is dark and full of terrors. It would make more sense to me if it were Intelligence saves, to protect rangers from mind flayers, but whatever.
Stalker’s Flurry turns a missed attack into a mere feint – once per round when you miss, you make a free attack.
Oh look, 11th level – a way to boost reliability rather than potential damage. It looks like they’re designing inventive ways to grant something less powerful than Extra Attack (2).
Stalker’s Dodge is an odd little conditional defensive feature, spending your reaction to impose disadvantage on an attack if it doesn’t have advantage. It’s not particularly impressive as a 15th-level feature (compare it to the Protection Fighting Style), but the archetype has enough else going on that this didn’t need to be great also.
I like the Deep Stalker pretty well, overall. It communicates its combat approach clearly and with malice aforethought, while cleaving tightly to theme. If Stalker's Flurry gave a 1d6 or 1d8 damage boost to the follow-up attack, it would be about perfect to me, but I'm stuck on feeling like rangers don't deal enough damage.
Shadow Sorcerous Origin
A more sinister sorcerous origin was just a matter of time, and some fan works have already plumbed this idea. Unearthed Arcana's version emphasizes the disturbing nature of a Shadowfell-linked sorcerer with a table of 1d6 Quirks, which are a nice touch. I would hope that DMs of Shadow sorcerers really enjoy emphasizing the character's quirk, possibly even granting it a meaningful game effect every now and again.
Beyond that, the Shadow origin grants:
Eyes of the Dark, or: I hope your party and the DM like making tons of attacks with disadvantage while you're totally fine. Gaining darkvision is fairly trivial. Getting to cast darkness for 1 sorcery point rather than the standard 3, and doing so from 1st level, is a pretty big deal. The clincher is that your darkness effects from this ability don't impede your sight.
Pair this with a fine chianti a warlock with Devil's Sight for best effect. The one merciful note is that darkness has a Concentration duration, so you can't just blanket vast areas with it.
Strength of the Grave, or a verbatim lift of Undead Fortitude (the zombie ability that makes them so horrible to fight). You can't rely on it in a bad situation, but when it works, it's really nice.
Hound of Ill Omen is an odd summoning ability that creates a single-target dire wolf. Did I mention that this playtest document is dark and full of terrors? This thing is pretty amazing, and obscenely good for 3 sorcery points and a bonus action. I can't help but like it, though. Also, it doesn't seem to have a Concentration-linked duration like most conjurations.
You gain this ability at 6th level. I wonder: at what point in the game a CR 1 creature is no longer a good investment of 3 sorcery points?
The best part of this feature might actually be that the hound imposes disadvantage on saving throws against your spells while it is within 5 feet of its target.
Shadow Walk is a shadow-to-shadow teleport, 120-foot range, as a bonus action. Big fan. This is a very good power, but we're talking about 14th level here.
Shadow Form should be renamed Spectral Form, because shadows (the MM creatures) don't have anything like this, while specters have exactly this (between their damage resistances, damage immunities, and incorporeal movement). For 3 sorcery points and a one-minute duration without requiring Concentration, I suspect this should be your opening bonus action in every fight at 18th level and above, unless the enemy only has force damage. It would be hard to ask much more defense and mobility improvement from a power.
It's weird that they gain resistance against radiant damage in shadow form.
The shadow sorcerer really needs a few more darkness- and necromancy-linked spells added to the sorcerer spell list to feel right. I get that they didn't like how the bonus spells of the playtest Storm Sorcerer worked out, but there are lots of storm-themed spells for sorcerers. Shadow and creepy-pasta, not so much. Other than that, I think Eyes of the Dark is probably too good, but the origin as a whole is very stylish.
The Undying Light Patron
Okay, first off, I can't stand the thematic content here. I know that some people are happy to see a non-sinister warlock, but to get to a non-sinister warlock you need to rework almost their entire spell list, and every last one of their Invocations. I also don't like that the patron is cosmic force (the Positive Plane) rather than an entity - a huge part of what makes warlocks interesting is that you can have a relationship (good, bad, or indifferent) with your patron. The story of Undying Light warlocks sounds like it's intended for a sorcerer instead. Sure, you can change every word of it for your own campaign, but that doesn't render this section immune to criticism.
My own story-side solution is simple. Pick one: your patron stole celestial fire from the gods and gave it to man; your patron was the proudest of the angels, glorious and doomed; your patron is a gnostic demiurge. But without something to contend with, the warlock just makes no sense to me.
The Undying Light warlock gets Quirks too, themed around maniacal devotion to light and the sun, and fear of the dark. It makes the warlock still less creepy, and more psychologically fragile. Other than item 4, destroying the undead, these are all basically the same flaw, though item 3 is the more active expression. Anyway, give these a pass or write your own, unless the whole table is going to enjoy watching your warlock have a nervous breakdown whenever you're in total darkness - all the more hellish in an Underdark campaign.
The patron's actual features:
Their Expanded Spells are mostly fire-based rather than light-based. This seems weird, all things considered. Surely it's not because there were no light-based spells of those levels?
Radiant Soul grants resistance to radiant damage (the least useful of all damage resistances), adds your Charisma bonus to damage with fire or radiant damaging spells, and gives you the sacred flame and light spells.
Unless enemies with cover is a constant problem for you, eldritch blast with the Agonizing Blast cantrip is still a lot better than this buffed-up sacred flame, but at least you get your Charisma bonus to other fire and radiant damage spells also.
Searing Vengeance is sort of a phoenix-rebirth thing that heals you, deals damage to enemies, and blinds them (within 30 feet) when you would roll a death saving throw, once per long rest. It's definitely impressive.
Interesting that this and Strength of the Grave appear in the same document - I wonder if they're seeing a lot of survivability issues with sorcerers and warlocks? To be fair, all of the Player's Handbook patrons grant something to improve survivability at 6th and 10th level. Some of them (hi, Fiend Patron!) are just a lot better than others.
I hate myself for saying this, but... the Phoenix Force is a good interpretation of the Undying Light patron that remains sinister enough to be a warlock.
Radiant Resilience is another survivability fixer, granting temporary hit points to the warlock and five allies. If it were more active during combat rather than passive at the end of a short rest, it would feel like more of a Leader power.
It looks kind of trivial compared to Dark One's Blessing, the 1st-level Fiend patron power. You do get to start battles with Radiant Resilience, but Dark One's Blessing offers the same number of temporary hit points, potentially many times per battle.
Healing Light is a much more direct Leader power. It grants a healing pool of 15d6 per long rest, which you can distribute in bursts of 1d6 to 5d6 per bonus action, by touch.
14th level is where other Patrons are granting unique, devastating damage or control powers. An average of 52.5 points of healing per day is nice, and takes some load off of the party's main healer or allows a paladin to play main healer. 14th level seems like a really weird time to change a class's party contribution.
The Undying Light patron needs more cosmological meaning and interest on the story side. The mechanics are fine, even if they feel like a warlock shopping at the cleric store. If nothing else, I like seeing new content that doesn't stay within the lines of things that have been established and retreaded from prior editions.
Also, they need to change the patron name so that it doesn't step on the toes of the already-in-print Undying patron, from the Sword Coast Adventurer's Guide.
There's nothing really crazypants in this playtest document. I'm probably more concerned about the Fighting Styles than anything else here, because they affect the greatest number of classes and interact with feats, sometimes oddly. Also, Tunnel Fighter with one or both of Polearm Master and Sentinel is just out of control - near-total stickiness covering either a 15-foot square (no reach weapon) or a 25-foot square (with reach weapon). The Shadow sorcerer is the one I'm most interested in playing, as the Deep Stalker feels too-cool-for-school to me, and I've explained my issues with the Undying Light theme.