The Fiend Warlock build - Baldur's Gate 3 (BG3)

The Fiend Warlock Build

The Fiend subclass is the most powerful one in terms of raw powers for Warlocks. You get a wide array of Elemental spells, that easily can burn or freeze multiple enemies to death. In addition, the Patron provides some control powers, like Command and Blind, allowing you to take control of the foe's destiny.

Another great aspect of The Fiend is that you get temporary HP after each kill. So you are able to tank more damage, allowing you to stay in the frontlines if the need arises. We also get access to Warlock spells, up to the late game.

And finally, Eldritch Blast will be the backbone of the build. It is the most powerful cantrip in the game once you obtain all the Eldritch Invocations, giving you both a huge damage boost and unprecedented control over the battlefield.

So if you are interested in taking The Fiends support, let's dig into the build

Starting the Game

Let's start with the early game. I would go into what are the best Races, Abilities, and Skills for The Fiend. Some of these choices are very impactful as you cannot respec them.

Races

Picking a race provides various benefits - abilities, dialogue options, looks, etc. Going with Githyanki gives you medium armor proficiency, however, something like Hal-Elf or Human provides Shield proficiency

Race	Features	Description
Githyanki	Martial Prodigy	This race is probably the best choice for this build. It gets Medium armor proficiency, Mist step, and other improvements that are very relevant for warlocks.
Drow	Drow Weapon Training Superior Darkvision Fey Ancestry	Drows get Superior Darkvision allowing them to see 24 meters in the dark. Moreover, at level 5 they gain Darkness, saving you a warlock spell slot.
Drow Half-Elf	Civil Militia Darkvision Fey Ancestry	This particular build, it is a weaker version of Drow due to the shorter Dark Vision. But they still come with other benefits - Faerie Fire and Darkness spells in later levels. Moreover, they get shield proficiency.
Asmodeous Tiefling	Darkvision Hellish Resistance Mage Hand - create a spectral hand that can manipulate and interact with objects	Asmodeous Tieflings get good spells at levels 3 and 5 - Hellish Rebuke and Darkness. They can be cast once per long rest and will save some spell slots for Warlock.

Class

Overview
Warlock
Features
Warlock Spell Slots	These spell slots can be used to cast spells and refill each Short Rest.

Cantrips

The Warlock class has one of the most iconic and strongest cantrips in the game - Eldritch Blast. In addition, we can select a few more and use them based on the situation.

Cantrip	Description
Eldritch Blast	Mandatory cantrip. At first, it may not seem super strong, but this will change at higher levels. It can increase its damage with Charisma and knockback enemies. From level 5 you can release two of them
Friends	If you are the main character and do most of the dialogues, this is also a good choice as it gives an advantage during rolls.

Subclass

Overview
The Fiend
Features
Dark One's Blessing	When you reduce a hostile creature to 0 hit points, this gift from your patron grants you temporary hit points

Spells

Spells	Description
Command	A very powerful crowd-control spell. It only works for one turn, but it does not need concentration. You can force the enemy to lie on the ground, run away, drop weapons, etc.
Hellish Rebuke	A decent spell early in the game. It deals good damage and activates when enemies are attacking you.

Abilities

Ability	Value	Description
Strength	8	We do not really need strength as we will be avoiding close combat
Dexterity	16 (15 + 1)	This is a decent amount of dexterity. With it, we fully utilize Medium Armor and gain +2 Armor Class. Moreover, this will give a high initiative so that you can start casting spells as early as possible.
Constitution	14	This is an important ability as it will determine our HP pool and decrease the chance that your Concentration will be broken while casting spells. This will allow sustaining Darkness or Hunger of Hadar even if hit
Intelligence	8	Not really needed for us
Wisdom	10	Not important for us, just enough to not get a penalty from Wisdom saving throws.
Charisma	17 (15 + 2)	This is the main ability of the Warlock Fiend build. It determines your Spell damage and the Pact of the Blade will give a boost to weapon damage.

Skills

For skills, I often recommend based on how you are role-playing. However, to maximize the character's effectiveness, I would go for everything that is Charisma and dexterity-related.

• Deception
• Intimidation
• Persuasion
• Performance

Leveling Progression

Here is the detailed progression for the build to get you started. You can use it as a guideline because early games can be daunting and overwhelming. Later on, once you get the feel for the class you can start picking your own spell options that fit the playstyle.

Level 2

This is the first warlock level up and you get some cool boons. Mainly you can improve the Eldritch Blast cantrip with invocations. Moreover, you get a bonus spell slot

Spells

Spell	Description
Hex	The spell is good at weakening enemies, but more importantly, you can get additional damage for each hit you do. Combine it with Eldritch Blast for sustained damage against bosses or stronger foes.

Eldritch Invocations

These are unique invocations that further boost Warlock spells. They provide some nice unique effects and unlock spells. However, our goal is to mainly allow us to see in the dark and improve the cantrip - Eldritch Blast.

Invocation	Description
Devil's Sight	Taking this will allow us to see in normal and magical darkness. If your race has dark vision, you could delay this till level 5, and take Agonizing Blast instead.
Repelling Blast	Eldritch Blast now knocks back. You can throw off enemies the ledges or to the chasm, where they die instantly

Level 3

Nice! Now we are ready to start rocking. This level expands our options and gives some cool stuff, let's look into it. The most important thing is that you unlock level 2 spell slots and a Pact Boon which gives unique effects to Warlocks.

Spells

Now you get level two spells which greatly improves your combat prowess. Here is what I recommend getting:

Spell	Description
Darkness	A truly powerful option, especially if enemies don't have a vision in magical darkness. This can trivialize many of the fights. You can safely stay in it, and just spam spells and Eldritch Blast. Note: If your race gives this spell on level 5, do not take it, and save a spell slot
Cloud of Daggers	The spell allows you to summon daggers that damage multiple enemies in a medium area. This is perfect to cover a choke point or force enemies to take damage in order to reach you. They take damage two times - when it's cast and when their turn starts.

Pact Boon

A gift from your patron. I suggest choosing one of these

Pact Boon	Description
Pact of the Chain	Gain a familiar that can be summoned every short rest. They have unique effects that can damage and debilitate enemies. Moreover, they can tank a few hits and scout areas.
Pact of the Tome	This option gives additional cantrips, which may not be useful at first. However, once you reach level 5 you gain Deepened Pact feature. It allows casting three additional spells without spell slot usage. If you wish to go super spellcaster, choose this one.

Replace Spell

Because we got to level 2 spells, switch Hellish Rebuke to:

Spell	Description
Scorching Ray	You can summon fire rays, that can hit multiple enemies. Moreover, the spell deals more damage than Hellish Rebuke, so it's a better option. Add hex into the mix, and you get a huge damage boost

Level 4

This is a big milestone - Congratulations! We get the first Feat that will give unique effects.

Cantrips

I recommend taking this cantrip:

Cantrip	Description
Minor Illusion	Next level you will get Hunger of Hadar. Before casting it you can attract enemies to one place from stealth, which will be deadly in damaging all of them at once.

Spells

I would like to avoid any more concentration spells as you can only cast one at a time, and the ones we have are already versatile. Due to this, I take one of:

Spell	Description
Misty Step	Allows changing position using a Bonus action. If you are Githyanki, do not take it as you already get one from the Race bonus
Hold Person	Freeze someone in place and then gang on them with melee attacks for guaranteed critical hits.

Feat

Feat	Description
Ability Improvement	Take +2 Charisma, which will give you a higher Charisma modifier, it will be important in the next level as it will increase the damage of each blast

Level 5

Level 5 will unlock some good things. First, you get the additional spell. Next, you unlock level 3 spell slots, so all your spells will now be upcast. And last but not least you unlock another Eldritch Invocation. Oh and I almost forgot the biggest thing:

Feature	Description
Deepened Pact	Pact of the Chain: Your familiar gains an Extra Attack. Pact of the Tome: You gain Animate Dead, Haste, Call Lightning once per long rest. perfect for pure blaster Warlock

Spells

At last, we can take the Level 3 spell. This is a huge improvement:

Spell	Description
Hunger of Hadar	The scariest spell you can use at this time. Use it to cover enemies and force them to move out of the fog. This will damage, blind, and slow them. Wait outside with your allies and use Eldritch Blast to shred them while they struggle

Eldritch Invocations

Invocation	Description
Agonising Blast	Improves Eldritch Blast damage by including your Charisma ability modifier in the damage calculation
Fiendish Vigour	Without using any spell slots you can expand your life temporarily. This is a valuable option for the Fiend build.

Replace Spell

To be honest I do not think anything could be removed at this moment. Well, maybe a Command spell. However, it is very valuable crowd control, that does not require Concentration

Level 6

This level-up will provide a unique Subclass feature based on the subclass you have. Because our protector is The Fiend, we get Dark One's Own Luck.

Feature	Description
Dark One's Own Luck	Call on your patron to change your fate and add a 1d10 to an Ability Check once per Short Rest.

Spells

Spell	Description
Fireball	A remarkable spell that does tons of fire damage. Very good against multiple smaller enemies.

Level 7

Once you reach this level your Warlock will gain the first level 4 spell. Moreover, few new Eldritch Invocations will be unlocked that you can choose to further improve your arsenal of spell choices.

Spells

It is hard to say which spell you should pick. Overall, none of them are something that could provide a huge difference in the build. So I would suggest a few options, and pick one:

Spell	Description
Blight	A powerful single-target spell, it has 8d8 rolls and can one-shot most medium enemies.
Wall of Fire	Create a wall of fire that damages any enemies that pass or are near it. I recommend first testing it if it fits your playstyle as it could be an alternative to fireball.
Hypnotic Pattern	Very deadly against low Wisdom enemies. The spell has a huge area of effect. The only downside would be that it only works for two turns, but this should be enough to take out a few foes.

Eldritch Invocations

Again, we get to choose an additional Eldritch Invocation. Sadly there are not many that are truly powerful.

Invocation	Description
Armour of Shadows	Without using spell slots you can cast Mage Armour that gives 13 Armour Class. Add the bonus dexterity that you have and shield (if you use it), resulting in 18 Armour Class.

Level 8

Another great milestone for The Fiend build. We get another spell selection and Feat.

Spells

Spell	Description
Banish	Can totally remove an enemy from the battlefield for two turns. This is a great Crowd Control spell giving you time to deal with smaller or less dangerous opponents.

Feat

Feat	Description
Spell Sniper	I recommend taking this one, as it will give a higher critical chance, with your spells for higher damage. Take any cantrip, Ray of Frost may be cool, if enemies are wet

Level 9

Warlock unlocks level 5 spells. I think they are very good offensive choices

Spells

Spell	Description
Flame Strike	A very powerful spell that does good fire and radiant damage. In addition, it has a small Area of Effect.

Eldritch Invocations

Most of the offensive invocations have been covered so here is what you can choose to improve utility and quality of life:

Invocation	Description
Otherworldly Leap	You can cast the Enhance Leap spell. Can be useful for exploration, but at this stage in the game you probably have another source for this spell.
Whispers of the Grave	You can cast Speak with Dead without expending a Spell Slot.
Beguiling Influence	You invoke your patron's bewitching charm. You gain proficiency in Deception and Persuasion Skills.
Fiendish Vigour	Get additional temporary hit points. The spell can be cast without using spell slots. If you have not taken this one yet

Level 10

Level 10 gives a new cantrip, spell, and more importantly, subclass action based on the patron we chose.

Action	Description
Fiendish Resilience	Choose a damage type and become resistant to it. You can pick a new damage type for each Short Rest. You can only have 1 type of Resistance at a time.

Cantrips

Cantrip	Description
Bone Chill	Can be useful in some encounters as you can disable enemy healing and greatly weaken undead enemies.

Spells

Spell	Description
Cone of Cold	A decent option that targets multiple foes in a cone. The downside is that it does not create any ice or water surface, so besides damage, there are no pros in using it.

Level 11

This is the last level in Warlock. We will take the next one as Sorcerer, to better optimize the build. Level 11 provides us with Mystic Arcanum - a single level 6 spell. Last, we obtain the third spell slot, greatly boosting your damage potential per single short rest

Spells

This is the last spell that we can take from the Warlock list. I would recommend:

Spell	Description
Counterspell	Another powerful spell that can counter almost any spell that foe casts. Even if you don't use it often, it is good to have it as it will notify you of what enemies are casting and let you decide the next steps

Mystic Arcanum

Spell	Description
Circle of Death	A very powerful AOE spell that deals necrotic damage. The big caveat is that it also hits allies, so its best used early in combat, while no one has mixed in between
Arcane Gate	This spell is useful in some circumstances where there are special mechanics. So if you are content with your damage output, you can get this one and be ready to use it when you see a need (and there will be a need for it in the story)

Replace Spell

At the next level, we will take Storm Sorcerer, which will give us very high mobility after spellcasting. Due to this, you should replace Misty Step with something else.

Level 12 - Sorcerer Lv 1

For level 12, there is nothing really much that will bring us benefits. We have most of the spells that we need, Eldritch Invocations do not give much benefit anymore, and The Fiend already has all the required feats.

Due to this, I recommend multiclassing into level 1 Storm Sorcerer. It will give good mobility without using spell slots - Tempestuous Magic. Moreover, you will get two level 1 spell slots, that can be used to cast Shield. This is a very powerful spell that can make you avoid most attacks during 1 turn.

Class

Overview
Sorcerer
Features
Spell Slots	These can be used to cast spells and are restored each long rest

Cantrips

Cantrips	Description
Mage Hand	Quality of Life spell, that you can use to summon an invisible hand. It can solve some puzzles, pick and throw objects. It can also shove enemies from ledges
Fire bolt	Use this cantrip to deal moderate damage or light up barrels with oil. Perfect if you want to save spell slots
Shocking Grasp	You can deal lightning damage that are close to Warlock without penalties
Blade Ward	For two turns decrease slashing, bludgeoning, and piercing damage in half. In theory, this means doubling the HP. The good thing is that this does not require Concentration.

Spells

Spell	Description
Shield	Mandatory pick. Expend a level 1 spell slot to increase your Armor Class by 5. This is a reaction just before the enemy hits. This gives a huge boost to survivability
Thunderwave	Do you see an enemy close to the ledge? Or they are close to you? Use Thunderwave to knock them back and deal thunder damage. It can instantly kill foes that are thrown from the ledge.

Subclass

Overview
Storm Sorcery
Features
Tempestuous Magic	After you cast a Level 1 spell or higher you can Fly as a bonus action until the end of your turn without receiving Opportunity Attacks.

General Tips

Now I would like to cover some general tips on how to play The Fiend melee build. There are multiple things to have in mind as this subclass is very effective both at long and close range.

Hex and Multihit attacks

When you are fighting a stronger enemy, that will take a few turns to take out, use Hex on them. This will give bonus necrotic damage for each hit you make. Although you would think that is hard, but from level 10 Eldritch Blast does 3 hits. Moreover, Scorching Ray does 6 hits with a level 5 spell slot.

So each of these will deal bonus damage, greatly increasing Fiend's spellcasting potential

Control Eldritch Blast effects

With Eldritch Invocations you unlock Repelling Blast for your Edlirtch Blast. This allows knocking back enemies 4.5 meters. However, sometimes you may not want this effect - you need additional loot or the enemy will leave the area of effect. You can add the passive effect from the Spellbook screen (K button) and add it to the quick bar

All of your spells are upcast by default

When you are using a spell it is by default upcast to the highest level. What does this mean? For example, a level 2 spell Scorching Ray will be cast as a Level 3 Spell once Warlock is level 5. This is different from other spellcasters who can choose what level spell slot to use

This forces, you to make a decision on how to best optimize what you have.

Short Rest after each battle

Although Warlock has two spell losses most of the game and gets the third one later, it can restore them with a short rest. This is different compared to other casters who need to do a long rest to fill them up again. Of course, the downside is that you have less of them

Conclusion

Thank you for reading The Fiend Warlock build in Baldur's Gate 3. We covered all the main aspects of creating a powerful spellcaster that utilizes gifts from its patron to rain fire. Moreover, you have general warlock cantrips like Eldritch Blast to blast and control the battlefield against foes.