D&D 5e: Great Old One Warlock Guide
Role in the Party
Sometimes, searching in dusty tomes of eldritch lore or delving deep into ancient ruins unearths secrets that should better be left buried. The Great Old One Warlock made this mistake; and found themselves noticed by gods primordial or cosmic, and granted a fraction of their power, but at a heavy cost.
Now, as a scion of the Elder Gods, the Great Old One subclass walks among mere mortals with the whispers of a being great and terrible inside its head. Foes are terrified into submission, or rent asunder with blasts of extradimensional force, while allies benefit from the Warlock’s powerful spellcasting, and may want to let them take the lead in social situations, where the character brings their (slightly unhinged) force of personality to the fore.
This guide breaks down the Great Old One subclass, the abilities it brings to the base Warlock kit, and potential ways to create an effective build.
Great Old One Features
Expanded Spell List: The Great Old One Warlock can choose to learn the spells below at the appropriate levels, and these spells count as Warlock spells for the class. Taken as a whole, these are a decent list of spells, with some powerful, choice picks.
Dissonant Whispers: Solid damage for a level 1 spell, plus the enemy has to move away from the caster (and potential take opportunity attacks) if they fail their save. Versatile and effective.
Tasha’s Hideous Laughter: If an enemy fails their save against this, it’s an absolute disable. They’re prone and incapacitated, so can’t do anything. They can save again at the end of every turn, and if they take damage, but this can still definitively lock one target out of an encounter for a turn or two to let the party deal with the rest.
Detect Thoughts: The effect is incredibly useful, and this is precisely on-theme for the GoO, but the spell is severely hampered by the Warlock’s lack of spell slots.
Phantasmal Force: One of the most powerful single target debuffs in the game, with a permissive GM. The effect is as flexible as the player, it targets a traditionally poor save for many creatures (INT,) it can replicate many other effects, and deals a small amount of damage every turn as well.
Clairvoyance: Create a magical security camera that either sees or hears things from the position you cast this. The fact that the duration is only ten minutes, it needs concentration, and it’s a visible flying orb of light limits the utility of this.
Sending: So this spell lets me send a message of only 25 words to a creature I know, and they get to respond, once. This costs me one of my two level 3 spell slots. Why would I cast this?
Dominate Beast: Turn an animal into a willing slave for a minute (or ten minutes if upcast at 5.) It targets WIS, which many beasts have a low save in, and gives you a free ally for the duration. Plus, the image of turning the enemy Ranger’s pet bear on him is hilarious.
Evard’s Black Tentacles: A big area of difficult terrain, the ability to restrain creatures, and ongoing damage make this a very solid control spell that’s effective enough that it might be cast in almost every hostile encounter.
Dominate Person: The effect is powerful, but a lot of humanoids have good Wisdom saves, and anyone hostile gets advantage on it, as well. It’s much more powerful when upcast, but the Warlock can’t do that, as their 6th level spells and above are Mystic Arcanum, not spell slots. Leave this to the full casters.
Telekinesis: The ability to move and restrain creatures, rip the weapon out of the giant’s grip, and use this as a more powerful Mage Hand that can carry up to 1000lbs makes this feature a solid green.
Awakened Mind: Telepathic speech to any target within 30ft. Eh, this is fine. It was stronger before subsequent books brought out racial archetypes and feats that let you do exactly the same thing, at much less opportunity cost, and seeing what other Warlocks gain at level 1 only increases the disappointment.
Entropic Ward: At level 6, gain the ability to spend a reaction as you’re attacked, and that attack is made with Disadvantage. If that attack misses, your next attack against the same target is made with Advantage. The ability can only be used once and refreshes on a short or long rest.
The second part of the ability kills it. If this subclass was released in 2022, this ability would probably scale with your proficiency bonus. That would start its uses at 2, the same amount you’d get from a single short rest (the expected amount per day), and scale up to 6 uses per day.
As it is, this is one third of the Lucky feat. Except it can only be used on enemy attacks. The Advantage on your attack rider would be nice if it didn’t only apply to one attack roll. Even just casting Eldritch Blast can make up to four, depending on level, and that’s a cantrip. Every character will get use from this, but it doesn’t feel good.
Thought Shield: Gain resistance to psychic damage, and reflect any psychic damage you do take back to the source.
The GoO Warlock also gains a ribbon ability which means its thoughts can’t be read unless it allows it to happen.
In certain campaigns, this ability is utterly useless, as psychic damage and mind reading are niche abilities among a lot of different types of enemies. In other campaigns, especially ones that deal heavily in Aberrations like Mind Flayers, this is straight overpowered. Resistance to the principal damage type and immunity to having your mind read is a great way to frustrate the DM in these cases.
Create Thrall: Finally, a good ability that plays into the theme of the class.
Touching an incapacitated humanoid lets you permanently charm them, as well as communicate with them as long as you’re on the same plane. With no save. The GoO Warlock can only have one thrall, and the effect can be disjointed by remove curse, or by removing the charm effect.
Still, this has massive utility in and out of combat. Incapacitate an enemy (with, for example, Tasha’s Hideous Laughter) then touch them and they become your best friend. This lets you send the Orc scouting through the dungeon for you, telepathically telling you where every other enemy is on the way.
Granted an audience with the noble ruler of a major town? He’s also your best friend until you decide he isn’t. (Or you can skip the preamble and fly into his bedroom while he’s asleep, and thus incapacitated.)
While this isn’t going to break games in half as some abilities do, it’s a tool that’s as flexible as the player using it can be, plus it’s just really good fun.
The base Warlock kit excels as a blaster. Refreshing spell slots that are always cast at the maximum level are perfect for laying down big AOEs of hurt, and the Warlock spell list has a fairly good selection of spells that fit this purpose. (Shatter, Hunger of Hadar, Synaptic Static.)
The spell list of the Great Old One offers up another great choice, Black Tentacles, which, like many of the Warlock’s damage spells, also builds in some ready crowd control as well.
The rest of the bonus spells also offer an impressive level of power, especially at low levels, which are some of the strongest single target debuffs in the game at the level they can be cast. Still, it’s worth remembering that, for much of their adventuring career, a Warlock has two spellcasts per day unless rests are available, and will spend a lot of their time casting Eldritch Blast. So it’s worth spending some Invocations to boost the damage and utility of the cantrip.
The Great Old One is particularly good in campaigns that are heavy with monsters that deal psychic damage, and want to mess with the party’s minds. Once hitting mid levels, the GoO gains some impressive defenses against both of these things, which can easily derail a GM’s plans.
Out of combat, the subclass has the right stats and skill options to make an effective face. Leaning into this, and into the mind-altering flavor of the class, can create a character who is a supremely effective manipulator, psychically whispering to their allies as they mess with the consciousness of anyone who opposes the party. This is an incredibly fun, but risky, playstyle. Trying to subvert the mind of the King is exactly the sort of thing a half-addled madman might do, and that plays into precisely what the Great Old One should be.
The Great Old One subclass has nothing that makes it a good melee combatant and very limited defensive options. (Entropic Ward! Yay!) Pairing that with a subclass that has a d8 hit die and only wears light armor equals a class that doesn’t like taking any hits.
The Warlock is also a spell starved class that suffers from a serious lack of resources, especially at low levels. The GoO does nothing to fix this, meaning that on days where the party can’t short rest, most of the character’s in-combat rounds are going to be spent casting Eldritch Blast.
Lastly, the Great Old One is simply less powerful than many of the subclasses that have been published in newer books. The abilities it has are low in uses, and generally low in power, especially if directly compared with the abilities that other subclasses get at equivalent levels.
Fortunately, the base Warlock class is strong enough that while choosing to play a scion of the Great Old Ones isn’t actively harming a character, it is considerably weaker than many of the other possible choices available at character creation.
Best Race Options
Protection Aasimar: Good stats, two damage resistances, Darkvision, and most importantly a once per day flight option and damage boost.
Fairy: Constant, unlimited flight is one of the biggest bonuses for a long-range blaster character like the Warlock. Extra spellcasts on a spell starved class are also very nice, as are the flexible stats.
Simic Hybrid: Darkvision, solid stats, and two interesting benefits that can add movement flexibility, toughness, or utility.
Choosing the Right Skills
Warlocks don’t have many skill options but do have stats that lean them towards being very good at the social aspect of the game.
Persuasion is the most used social skill, but the Warlock also has easy explanations for Deception and Intimidation.
Knowledge skills are also always handy and have a nice tie with the subclasses theme and fluff, so it can be nice to pick up one or two. From here, any remaining slots can be spent on thematic skills, or options the party otherwise lacks.
Metamagic Adept: There are some powerful metamagic options in the Sorcerer’s ability list, all of which would be incredibly useful for a Great Old One Warlock.
We would lean towards two choices. Quicken Spell allows the Warlock to cast one of their leveled spells as a bonus action, meaning that it can be cast in the same turn as a cantrip. Use a boosted Eldritch Blast to shove enemies together, then drop an AOE on them, or disable one enemy and blast another.
The second option is for campaigns that might be heavier in the intrigue side of things. Subtle Spell allows the Warlock to cast spells without somatic or verbal components. That means no outward indicators that a spell has been cast. And the GoO subclass has a lot of ways to meddle with people’s minds. And now it can do it without anyone else knowing.
Eldritch Adept: The Great Old One isn’t a melee character, so it’s not going to be hurting for stat increases past getting CHA to 20. This lets later ASIs be freely swapped for things like Eldritch Adept, which offers another Invocation option, without harming the character.
Spell Sniper: Double the range of all spells and ignore cover on spell attack rolls. You’re getting this for Eldritch Blast, but it’s honestly worth just for that alone.
A bonus attack cantrip from any class’s spell list is also a nice bonus to diversify damage options.
Courtier: Two essential social skills and two languages are exactly what a Warlock needs to be the party Face.
Urchin: Two sneaky thief skills, which most Warlocks will have the right stats for, as well as the Disguise Kit and Thieves Tools build a more Roguish character.
Archaeologist: Two utility skills, a language, a choice of exploration tools, and an easy in for how your character discovered their great and terrible knowledge
Oath of Watchers Paladin: Focus more heavily on melee by taking levels in Paladin. For this subclass, it’s recommended to start as a Paladin for the proficiencies needed to be an effective warrior. The multiclass can go either way, gaining Extra Attack from Paladin or Warlock, using Blade Pact.
Melee attacks and Smites using spell slots from both classes would be the main order of the day, backed up with the occasional powerful spell cast.
Oath of the Watchers also fits perfectly with the thematic elements of the class, offering abjuration against outsiders and protection against magic. Whatever Elder God thirsts for your soul is going to have to fight for it.
College of Spirits Bard: The Bardic package is very nice for Warlocks, turning the class into more of a supportive/buffing character, while also adding more debuffs and out-of-combat utility.
The Spirit Bard leans into this, gaining a superpowered Guidance cantrip, as well as the ability to gain random boosts from a small table as a bonus action, many of which are surprisingly powerful effects. 3 levels to gain the ability is enough, though this multiclass could easily take a handful of Warlock levels to gain important Eldritch Blast buffs, then focus more heavily on the Bard side.
Shadow Magic Sorcerer: Sorcerers multiclass well with Warlocks. Extra spells, spell slots, and Metamagic offer a wide range of abilities, though it’s generally better to focus on one of the classes, and only take a maximum of 3 levels in the other.
3 levels of Shadow Sorcerer offer strong Darkvision, the ability to cast Darkness that the character can see through, and a once-per-day refusing to die ability, all of which are very nice, plus the usual Sorc. benefits. More investment brings a shadowy summon that affects an enemy’s ability to save against your spells, which can easily be flavored as an extraplanar horror.
So why not take the Aberrant Mind subclass instead? The answer is simple. The early levels of both subclasses have very similar abilities, meaning that the character isn’t gaining any interesting abilities, only spells.
Would I recommend playing a Great Old One Warlock?
It’s unfortunate, but the Great Old One Warlock seems to have been left behind as 5e progressed. A lot of its abilities are underpowered (Disadvantage on one attack roll per short rest? Really?) and what’s left doesn’t fit the theme of a spellcaster channeling the abilities of Elder Gods.
As an example, the Aberrant Mind Sorcerer fits the theme so much better, with vastly stronger abilities, even the ones that directly compare to what this subclass has available. If you’re dead set on playing a Warlock, the Undead patron from Van Richten’s Guide to Ravenloft is also powerful and fun to play, with abilities that feel similar in tone.
While the subclass isn’t bad, it is distinctly underpowered, especially compared to a lot of the newer content that’s been released. It’s possible to still have fun playing the Great Old One, and you’re not actively harming your party by choosing to do so, but it’s worth being aware that there are better options out there.