It's a weird time as a D&D fan. With only a few exceptions, I've been a big fan of the 50th-anniversary revamp to the D&D rules (again, I foresee some future book doing with Background what Tasha's did with Races - namely de-coupling specific ability score bonuses from them). But between all the ways that WotC and its parent company Hasbro has repeatedly made your classic "greedy corporate" decisions that have really hurt good will toward the game, and also the recently-announced departures of both Chris Perkins and Jeremy Crawford, and then a bunch of backlash against the "5.5" edition (which was inevitable,) it's all just a bit foggy.
When I first cracked open the Player's Handbook in 2015, the class that most inspired in me the desire to play a character (it wouldn't be until 2018 that I actually got to play a PC) was the Warlock. I just felt that the inherent story behind the premise of the class was really exciting.
And it was the Great Old One patron whose flavor spoke to me the most. Naturally the most "obvious" default subclass for a Warlock is probably the Fiend, with its faustian bargains and such, somehow the class has always felt most fitting for a Great Old One, bargaining not necessarily with something malevolent but just truly alien.
Way back when, I wrote a character backstory for Conrad Nightfire, a young duke's son who was given a book on his sixteenth birthday that, in reading it, put his mind in contact with an alien entity known as the Shattering Tower. The madness that this inflicted upon Conrad led to a tragic accident that killed his father, but even as he rightfully should have assumed the role of Duke, he was sent off to a remote sanitarium. Initially benefitting from both the doctor who treated him and a friend he made at the asylum, things turned when his old doctor went missing and a new, cruel doctor took his place, imposing torturous "treatments" on the patients. This ultimately came to a point in which the Shattering Tower reached out to Conrad through his lobotomized friend (if indeed that's what happened - I'd leave a lot of the specifics up to the DM) and granted him his magical powers to escape the asylum.
Conrad suffers a lot of lost time, finding himself in places without knowing how he got there, and is on a quest to discover what all of this means, while fearing returning home to face the role he played in his father's death, not to mention the responsibilities he has now that he is the rightful duke.
So:
What we have, generally, is the following details: Conrad is a human, with the Noble background, and he's a Warlock with the Great Old One patron.
Part of his backstory involves his inheriting of the old journal that his friend, Old Delgado, from the asylum had been secretly keeping and hiding from the doctors. The journal (which I picture as one of those composition notebooks with the black-and-white static-like pattern on the front, though really whatever is the more period/genre-appropriate version) would be the basis of his Pact of the Tome.
I see him being a "Blastlock," and not going Pact of the Blade. The latter is, admittedly, something I think would be a lot of fun to play at some point (though I think it's hard to straight-class as a Bladelock, if only because a single Fighter or Paladin level solves a ton of their problems).
Naturally, as a Warlock, you aren't going to have the giant box of tools that a Wizard has. So, the primary job in combat, for old Conrad here is going to be to blast away with Eldritch Blast. That's honestly true for most Warlocks, but I guess the question becomes how we want to build things out.
As a Charisma-based character as well as someone with the potential for a lot of social connections (though at least to start off with, a refusal to invoke said connections,) I think we'd want to play as something of a "face" character. This could impact some of the Eldritch Invocations we pick up, along with some of the Feats we take.
If we wanted to go full combat-mode, the obvious thing would be to start off taking Agonizing Blast and Repelling Blast (both of which require level 2, but we could easily get Tome at 1 and then these two. Spell Sniper would also probably be an obvious feat to pick up.
But let's go level-by-level.
Currently, I'm mostly concerned with building to the level my most-played character is at, and my Wizard just hit level 8, so we're going to be there. So, let's just break this down level-by-level.
I think the hope here is to be capable in combat (as that's a factor in nearly every D&D game) but also try to be capable in social interactions as well.
Level 1:
With the Noble background, we can boost our choice of Charisma, Strength, or Intelligence. I think if I were going Bladelock and, for example, trying to hit the minimum 13 for Great Weapon Master, I'd give my +1 to Strength, but as our guy is really going to be more of a magic-focused warlock, I'm thinking we take +2 to Charisma and +1 to Intelligence.
If we're just assuming Point Buy, I'd get that 15 in Charisma, meaning with our background it's 17 to start off, and we'd get to 18 (+4) with a General Feat at level 4.
Now, given that Warlocks only get light armor and aren't a dex-based class, we're kind of going to have terrible AC no matter what we do. I think the goal will be to just stay away from attackers as best we can (party composition could be a major factor here - my Wizard almost never gets hit with melee attacks simply because we have two paladins and a fighter all there to tank for me). So, Con is more important to me than Dex, though I want both to be high.
If we wind up getting something akin to the Standard Array, we're probably talking 15 Charisma, 14 Con, 13 Dex (which could leave us open for Moderately Armored at some point,) 12 Intelligence, 10 Wisdom, and 8 Strength. I suppose we could dip down that Int to 11 (as it will go up to 12 with our Noble stuff) and then maybe get Dex to 14 (I think we can do that?)
Now, as a human, we also get an additional Origin Feat and an additional Skill proficiency. We're also getting Skilled for our Noble background. Magic Initiate of various kinds could be good here - we're already going to have a ton of cantrips, but we're going to be very flexible in which cantrips we can pick up anyway. It might be good to go MI: Wizard, and thus pick up the Shield spell. Thus, in the hopefully-rare cases where we do get attacked, we can potentially pop that AC up to something respectable.
As for cantrips, we're already getting Eldritch Blast and probably Prestidigitation from Pact Magic, then Pact of the Tome will get us several others. Let's say from our feat we'll get True Strike (giving us a good melee option before we get Spell Sniper) and Mage Hand, then Tome could give us Mending, Minor Illusion, and, oh, Spare the Dying I guess? (Message we don't really need because we can use our Awakened Mind at level 3). Then, for ritual spells, I guess we can pick up Find Familiar (we won't get a cool Chain-pact option, but it's still pretty cool) and Identify or Detect Magic (ritual spells are a little rough for a warlock during the levels where they want to concentrate on Hex).
Skill-wise, we're getting History and Persuasion from our background, but also three more from Skilled (as well as, I guess, potentially some tool proficiencies - but given that tools work in tandem with skills, I'm going to focus on those instead). Perception is always good to have. Insight would also be good for social situations. And then, I think Athletics could help balance out our terrible Strength (as a skill that is often called for). As a Warlock, I feel like Arcana and Intimidation (I could also imagine going Deception here - which might be a better choice if we want to really lean into things like the Actor feat and Mask of Many Faces) would be good options here, and perhaps with our Human bonus skill, maybe we grab Stealth. That's 8 skill proficiencies!
For our initial spells, Hex is actually plenty good at early levels, and I like Armor of Agathys as a way to weaponize our crap AC.
At level 2, we get Magical Cunning, (not to mention a second spell slot,) which will make us capable of casting spells a bit more frequently. We also learn a third spell. Charm Person, interestingly, is not concentration, but tons of creatures that were once humanoid are no longer. Still, on a more social-focused campaign, it probably would come up a fair amount - and when we get our Psychic Spells next level, we can even do this without alerting anyone to our casting of it.
We also get two more eldritch invocations, allowing us to pick up Agonizing Blast and Repelling Blast Agonizing Blast is, I think, the really mandatory one (and one I'd be tempted to take even on Bladelocks) but Repelling is also quite good, and lets us really lean into the "magic martial" identity of the Warlock.
At level 3, we get our Great Old One subclass. This includes learning Detect Thoughts, Dissonant Whispers, Phantasmal Force, and Tasha's Hideous Laughter (and our two spell slots level up). We can use Awakened Mind to create a two-way telepathic link with a creature within 30 feet of us. Psychic spells allows us to turn the damage of our spells to Psychic damage (which will not likely come up with our main damage spell, Eldritch Blast, as Force is usually better than Psychic) but more excitingly, we can cast Illusion and Enchantment spells without Verbal or Somatic components (still will need material components - though we have a few patron spells that don't require those). We also learn another spell, with 2nd level options now available. It's hard for me to not take Misty Step on any character I can, and while it won't scale in level, I think I'll still grab it.
At 4, we have our first feat. And this one's a real big choice: Warcaster is a really good feat for Warlocks, who really don't want to drop concentration on the spell they spent one of their precious spell slots on. Spell Sniper allows us to use Eldritch Blast in any combat situation. And then, the Actor feat is going to make us better at lying when disguised. I like this social-focused build idea, but I think I'd expect to have combat a bit more consistently. The truth is that we could eventually pick up all of these (and there's a good chance we would) but I'm going to focus on being more combat-capable to start with. And I think that, without a Con save proficiency, Warcaster will be probably the best call. (We could also combo True Strike with Dissonant Whispers!)
And, once again, another spell. Now, we need not pick a natively 2nd-level spell. Unlike a Wizard, who saves serious money (and most time, though my Scribe wizard copies things so quickly that he doesn't need downtime to copy spells) by picking the highest-level spells they can on level-up, a Warlock does fine by picking a well-scaling low-level spell. Cloud of Daggers (which is 2nd level) could play fairly well with our Repelling Blast invocation. I also like Suggestion.
Ah, right, we also get another cantrip. Minor Illusion, I guess!
At level 5, we're getting 3rd level spells, including Clairvoyance and Hunger of Hadar. We also get two more Eldritch Invocations. We can start building toward our social infiltrator stuff by picking up Mask of Many Faces. Then, especially now that we have Hunger of Hadar, Devil's Sight will help make up for our weak human eyes and allow us to see all the tentacle-weirdness that assaults our foes when we cast that spell (though, on an aesthetic level, I think of Conrad's patron as being less slimy tentacle stuff and more dusty white stone and giant geometric shapes in the hazy distance).
For our new spell at this level, Tongues could help us play the team diplomat. Fear is also very good and strong. Bit of a judgment call based on what kind of campaign we've had so far.
At 6, we get Clairvoyant Combatant. This allows us to weaponize our Awakened Mind, though this also requires us to get within 30 feet of a foe, when we usually want to stay farther away. That said, if we start 45 feet from them and just dip in and out, we can maintain a safe distance while using this.
And we have another spell. Dispel Magic is probably a solid option. Remove Curse might also be good, depending on how frequently we see people getting cursed.
At 7, we get 4th level spells, which means Confusion and Summon Aberration. The latter is going to probably be the main thing we use in combat, though we'll need a 400g material component for it. For our level-up spell, Banishment can be clutch.
We also get another Eldritch Invocation. We've honestly got a lot of the ones that make our build work. I'd certainly consider dipping into some of the old-rules ones (Grasp of Hadar with Repelling Blast can be very fun - while we don't get Spike Growth, if we have a druid pal we can do some nasty cheese-grating). Tomb of Levistus can be a literal lifesaver. If we want to stick to 2024 options, Gift of the Depths would be very nice in a campaign with significant underwater portions, though it's certainly situational - arguably Master of Myriad forms is the better choice, as we can give ourselves that Aquatic Adaptation, but also potentially get a way to disguise ourselves that will isn't illusion. Otherworldly Leap is also potentially good given how much better the Jump spell is now. And, we could, of course, pick one of the other Pact Boon invocations - while we already have Find Familiar, we could now get an exotic one (given his pursuit of arcane secrets, I think a Sphinx of Wonder feels like the right familiar for our character). I'd hope that my DM would allow me to swap out the Pact of the Tome Find Familiar if I did this one.
Finally, at 8, we get another feat, and another spell.
We could, of course, just push our Charisma to 20 at this point - this would make room in tier 3 to pick up things like Moderately Armored. Alternatively, though, if we're willing to wait until level 12 to max out our Charisma, we could pick up one of the feats we left behind at level 4. By this point, hopefully we have a good sense of the balance of social versus combat encounters we have in this campaign (I do find, as a DM, that I have a bit of a harder time making a social encounter feel like something with truly variable outcomes. Partially is that I have campaigns planned out perhaps too well.) In a more social campaign, I think Actor could be very good here. Otherwise, I'm probably taking Spell Sniper, though unless I really don't think Actor will help in the long run, I'll probably take it at level 12.
Now, for our spell at this level: Charm Monster is worth considering, given that as you get into higher levels, you're facing fewer and fewer humanoids. We could dip back to Mirror Image to give us a little more survivability, though I think its lack of scaling makes me question whether preventing 3 hits is worth one of our spell slots - ideally we're not even in a position to be getting attacked (the new Mirror Image is incredible on a heavily-armored Eldritch Knight). Fly is also good utility (hitting two targets at this level) and Dispel Magic is broadly useful.
So, how do we think Conrad will do?
As I see it, the standard operating procedure by this level will rely a lot on Summon Aberration as our concentration spell (the nuances and vagaries of Create Thrall can wait for another 6 levels). While Hex will stay up for a good chunk of the day, Summon Aberration is going to be very good damage for an hour as long as we can keep our guy alive.
Given the changes to the 2025 Monster Manual, the Slaad option for this spell is actually quite a bit better than it was - there are still monsters with resistance to slashing damage, but with the removal of the idea of "magic" damage, I think there are very, very few that have full immunity (I think the Ochre Jelly?) so our Slaad buddy could be quite effective. The Beholderkin does have the benefit of being ranged, though, as well as flying, which means it's very easy to keep them out of the fray (as long as the monsters are largely melee-limited, which is less common these days). One reason I think the Slaad looks very good right now is that they have health regeneration - as long as they survive combat, you can more or less assume that they're back at full health by the time another fight breaks out. They regen 5 HP per turn, so that's just 48 seconds to go from 1 HP to their (4th level casting) max of 40. The Slaad also does do more damage than the other two.
The Mind Flayer (which was the Star Spawn in Tasha's) is a bit more fragile in that regard, and does the same damage as the Beholderkin, but in melee. But it also has its Whispering Aura, which can potentially do a bunch of AoE damage. There are some downsides here, though: the Mind Flayer will damage allies (it doesn't hurt us, but we're going to be staying the hell away from the bad guys) and the Aura is a save for none. Now, it is our saving throw DC, which by this level, with a 19 Charisma, we're talking a DC of 15. If this works have the time, it's effectively 3.5 extra damage multiplied by how many monsters it can get near (the aura is 5 feet, so they have to be right up against it).
Of course, we can determine the options situationally. The Slaad could be very nice against a regenerating monster (which there are fewer of with the changes to Vampires). Probably best to assume Beholderkin as a default, though.
So, our first round of combat (or, if possible, before - because our Summoned Aberration does last an hour. In fact, it'd probably be reasonable to cast it before we start a short rest if we can) we spend an action to summon the Aberration. If we're near our target, we can also try a Clairvoyant Combatant to get inside the most prominent enemy's head (we're probably built to focus down the biggest threat).
The Beholderkin then makes two attacks for 1d8+7, or 11.5 on average, meaning two hits should average 23 damage.
Then, on subsequent turns, we join the Beholderkin with Eldritch Blasts, making two that deal 1d10+4, or 9.5, meaning 19 average damage.
That's 42 damage per round (obviously, this is before we account for hit chance).
Ok, let's assume we're fighting something with a, say, 17 AC (not unreasonable for a tough bad guy at level 8).
We have only a +7 to hit at this level (assuming we haven't gotten a Rod of the Pact Keeper or similar item). So, we need to roll a 10 or higher to hit, giving us a 55% hit chance. Our Aberration has the same attack bonus, which keeps this simple.
Beholderkin:
11.5x55%, or 6.325, plus 4.5x5%, or .225, so 6.55 damage per attack, meaning 13.1 damage per round.
Eldritch Blast:
9.5x55%, or 5.225, plus 5.5x5%, or .275, so 5.5 average damage per attack, and thus 11 damage per round.
Meaning we're pulling 24.1 damage per round.
It's not amazing damage, but it'll do better with enemies at lower ACs, and we're also bringing a fair amount of utility, with our giant catalogue of cantrips and also our various other Warlock spells.