Fiend Warlock Handbook: DnD 5e Subclass Guide

Introduction

Straightforward and effective, the Fiend Warlock offers mostly offensive options which improve the Warlock’s ability to kill stuff, but also offers some extremely potent defensive abilities. The Fiend is a blaster first and foremost, and is heavily dependent on fire damage, so consider taking the Elemental Adept feat.

The iconic Warlock subclass, the Fiend leans hard into the Warlock’s core capabilities, complementing them without adding any additional complexity. This makes it a very approachable subclass, which is likely why it was chosen for inclusion in the SRD over the Great Old One. Also, making pacts with the Devil for magical power is a classic fantasy trope.

Table of Contents

• Introduction
• Disclaimer
• Fiend Warlock Features
• Fiend Warlock Ability Scores
• Fiend Warlock Races
• Fiend Warlock Feats
• Fiend Warlock Weapons
• Fiend Warlock Armor
• Fiend Warlock Multiclassing
• Example Fiend Warlock Build – The Iconic
  • Ability Scores
  • Race
  • Background
  • Skills and Tools
  • Feats
  • Levels

Disclaimer

RPGBOT uses the color coding scheme which has become common among Pathfinder build handbooks, which is simple to understand and easy to read at a glance.

• Red: Bad, useless options, or options which are extremely situational. Nearly never useful.
• Orange: OK options, or useful options that only apply in rare circumstances. Useful sometimes.
• Green: Good options. Useful often.
• Blue: Fantastic options, often essential to the function of your character. Useful very frequently.

We will not include 3rd-party content, including content from DMs Guild, in handbooks for official content because we can’t assume that your game will allow 3rd-party content or homebrew. We also won’t cover Unearthed Arcana content because it’s not finalized, and we can’t guarantee that it will be available to you in your games.

The advice offered below is based on the current State of the Character Optimization Meta as of when the article was last updated. Keep in mind that the state of the meta periodically changes as new source materials are released, and the article will be updated accordingly as time allows.

Fiend Warlock Features

1. Expanded Spell List: Warlocks don’t get any AOE blast spells, which means that they often have trouble against crowds of enemies. The Fiend’s spell list offers several excellent options to address this.
   • 1st-level Spells: Burning Hands is a decent AOE, especially at low levels, and since Warlocks get armor and more hp than Sorcerers and Wizards, you can survive being close enough to melee to use it, however, I wouldn’t use it beyond very low levels. You’ll get more total damage out of Hex or other spell options despite Burning Hands’ scaling. Command is a great control/debuff effect and scales really well with your spell slots.
   • 2nd-level Spells: Blindness/Deafness is a powerful debuff, but allowing repeated saves can make it unreliable. Scorching Ray is a bit redundant with Eldritch Blast, but it scales very well and benefits from the same tactics.
   • 3rd-level Spells: A good AOE blast and a good area control effect. Fireball remains the best instantaneous AOE damage spell at every spell level until around spell level 8, and, while the Warlock can’t cast Fireball past 5th level, it still remains a perfect go-to AOE blast option. However, remember that you will often get better results out of spells with ongoing effects like Hunger of Hadar, and with so few spell slots you need to squeeze as much out of them as you can. Stinking Cloud is an ongoing AOE save-or-suck effect, but creatures within the area are Heavily Obscured so it’s hard to attack them. Hunger of Hadar is likely a better choice in most cases.
   • 4th-level Spells: Fire Shield is fine for “gish” builds, but, if you’re going for a Warlock gish you’re probably going to play a Hexblade. Fire Shield also seems redundant with Armor of Agathys, which notably lasts longer, provides temporary hit points, deals more damage to attackers, and scales with spell level. Wall of Fire is one of the best area control spells in the game and with the right invocations you can push and pull enemies through it to repeatedly capitalize on the guaranteed damage dealt when a creature passes through the wall.
   • 5th-level Spells: Flame Strike is Fireball, but a smaller AOE and worse damage. Sure, some of the damage is radiant, but if damage resistance is a problem, you should be using Eldritch Blast since nearly nothing resists Force damage. Hallow is very situational.
1. Dark One’s Blessing: This makes Fiendish Vigor considerably less important. It also makes it important that you occasionally pick off weak foes to ensure that your temporary hit points are up before you focus on more important foes. RAW the creature just needs to be hostile, so a permissive DM might allow you carry around a bag of angry rats and kill one whenever you need temporary hit points.
6. Dark One’s Own Luck: Adds an average of 5.5 to your roll, which is mathematically much better than what you get from Advantage (Advantage is worth slightly more than +3). Save this for crucial saving throws or if you’re desperate need to escape a grapple but can’t teleport or something.
10. Fiendish Resilience: This doesn’t specify restrictions on the damage type, so if you want to do Slashing for a while then switch to Radiant, you can do it. This is one of very few ways to get resistance to Force damage, but you still want to use this for common damage types like fire, poison, and slashing.
14. Hurl Through Hell: Only works once per day, but 10d10 damage is pretty great on top of whatever your attack was (let’s be honest: it was Eldritch Blast). The creature is also removed from the game until the end of your next turn, allowing you to temporarily banish the creature, and potentially place hazards in and around its space such as Hunger of Hadar, Wall of Fire, or the rest of your party.

Fiend Warlock Ability Scores

No different from a typical warlock.

Fiend Warlock Races

No different from a typical warlock.

Fiend Warlock Feats

No different from a typical warlock.

Fiend Warlock Weapons

No different from a typical warlock.

Fiend Warlock Armor

No different from a typical warlock.

Fiend Warlock Multiclassing

No different from a typical warlock.

Example Fiend Warlock Build – The Iconic

The Fiend is the iconic Warlock, so we’re going to build an iconic Fiend Warlock. We’re going to do stuff that’s exciting, flashy, and impactful. We’re also going to cast Fireball a lot.

Ability Scores

We’ll put our racial +2 into Charisma because and our +1 into Dexterity for better AC and Dex saves.

	Base	Increased
Str	8	8
Dex	15	16
Con	14	14
Int	10	10
Wis	8	8
Cha	15	17

Race

Custom origin tiefling because we’re an icon, but also we keep up with the times. Nearly any variety of tiefling will suffice, but for this build we’ll go for the classic because the innate spellcasting works well for us, but the custom the origin rules allows us to reassign then +1 Intelligence increase. Fire resistance is also fantastic.

Background

Noble because we’re fancy. This gets us proficiency in History and Persuasion. Persuasion isn’t on the Warlock’s skill list, which makes it essential for us to get it from our background. We also get proficiency in one gaming set and one language.

Skills and Tools

We’ll take Arcana and Deception from our class skills, then we get History and Persuasion from our background. We’ll put our gaming set proficiency into something cool like Dragon Chess.

Feats

At 4 we take Flames of Phlegethos, raising our Charisma to 18 and giving us some insurance against poor damage rolls with some of our subclass’s best spells. The retaliatory damage when you get hit is miniscule, so we won’t worry about that. We’re here for the firepower.

At 8 we’ll take Skill Expert to raise Charisma to 19, get Proficiency in Intimidation, and Expertise in Persuasion.

At 12 we’ll take Fey Touched for another +1 Charisma and some extra spellcasting.

At 16 we’ll take Metamagic Adept

At 19 we’ll take Lucky. We don’t really need anything else, and Lucky is the perfect feat for those situations.

Levels

Level	Feat(s) and Features	Notes and Tactics
1	Otherworldly Patron: The Fiend Dark One’s Blessing Pact Magic Spells Known: – Command – Hex Cantrips Known: – Create Bonfire – Eldritch Blast – Thaumaturgy (tiefling)	Take whatever you like for starting equipment. As long as you have some sort of light armor and a spellcasting focus, you’re doing fine. Eldritch Blast+Hex is your go-to combat option, but look for opportunities to make Create Bonfire useful in order to control the battlefield. Dark One’s Blessing makes it important we get the last hit on enemies if we don’t already have temporary hit points. Look for weak enemies to pick off.
2	Eldritch Invocations – Agonizing Blast – Devil’s Sight New Spell Known: –	We’re going for the iconic classics here: Agonizing Blast and Devil’s Sight. Once we can cast Darkness, we’re in great shape.
3	Pact Boon: Pact of the Chain Retrain Invocation: – Agonizing Blast -> Investment of the Chain Master New Spell Known: – Darkness	Pact of the Chain lets us get an imp familiar, and, if we’re going to be a Fiend Warlock, we’re going to take as much fiend-themed goodness as we can get. A quasit could also work, but quasits lack the ability to see in magical darkness, which makes your tactics much more complicated. We’re going to temporarily retrain Agonizing Blast into Investment of the Chain Master and make our familiar our go-to attack option for a few levels until the Imp’s +5 attack bonus stops being effective even with Advantage. In combat, our go-to tactic is to cast Darkness, walk it onto an enemy, and have our imp attack repeatedly. We can use our Attack action to have our imp attack once as its Reaction, plus we can use our Bonus Action to command it to take the Attack action on its turn for a total of two attacks. Ideally, both are made with Advantage. Thanks to Investment of the Chain Master, our imp’s poison damage DC is raised from 11 to 13. Constitution saves are frustratingly high across the level range, unfortunately, but the Imp’s two attacks per turn dealing 1d4+3+3d6 are potentially much more effective than our single Eldritch Blast at 1d10+3. If we assume a 50% success rate on the poison, that’s still an average of 10.75 damage per hit compared to just 8.5 with Agonizing Blast, and we get to do it twice per round. If your familiar dies (and it likely will), revert to attacking with cantrips. This level also allows us to cast Hellish Rebuke as an innate spell if something manages to see you to attack the darkness.
4	Feat: Flames of Phlegethos (Cha 17 -> 18) New Cantrip Known: – Scorching Ray New Spell Known: – Green-Flame Blade	Flames of Phlegethos both improves our Charisma and lets us reroll 1’s on fire damage dice. We’re going to rely heavily on fire damage, so that’s nice insurance against poor rolls. We don’t have Agonizing Blast at the moment, so Scorching Ray is a decent substitute for the usual Eldritch Blast tactics, especially if we already have Hex running. Scorching Ray will only be appealing when we’re well situated to hit a big single target. Eldritch Blast is similar, and doesn’t cost a spell slot, but in some cases you will want to do a ton of damage to one target all at once. This pairs well with Hex, but, since you can’t cast both in the same turn you’ll need to be reapplying Hex for it to work. It also pairs nicely with Flames of Phlegethos because we’re throwing a bunch of fire damage dice at our problems. I don’t expect Green-Flame Blade to see much use, but we’re leaning into fire damage, and sometimes you need to fire-stab something when they get too close. We have 16 Dexterity and a dagger, so we’re decently effective, but not going to amaze anyone.
5	New Invocation: – Agonizing Blast New Spell Known: – Fireball	And we’re back to Agonizing Blast just in time for our second ray to come online. Our imp’s attacks are arguably still better damage, but their attack bonus is 2 lower than ours, so they might struggle to hit without Advantage. More importantly, we now have Fireball. With Flames of Phlegethos, the damage will be marginally better, improving the average damage per die from 3.5 to 3.92. At 8d6 damage, that raises our average from 28 to 31.36. So, marginally better, but it’s not going to knock your socks off. This level also allows us to cast Darkness as an innate spell.
6	Dark One’s Own Luck New Spell Known: – Summon Undead	With Dark One’s Own luck, we have some insurance against poor rolls. This lets us do something fun but risky: We can drop Fireball at our own feet. We have resistance to fire damage and easy temporary hit points from Dark One’s Blessing. If you find yourself surrounded, drop a Fireball on the ground. At 31.36 average damage, we halve that to roughly 16. We can have 10 temporary hit points from Dark One’s Blessing, allowing us to fireball a crowd of enemies around us at the cost of roughly 6 hp. We’re unlikely to pass our own save, but if we come close and still fail, we can use Dark One’s Own Luck to try to pass and further mitigate the damage. Unfortunately, the temporary hp from Dark One’s Blessing won’t scale as fast as the damage from Fireball, but nothing screams “cool” like fireballing an enclosed space and walking out just slightly singed. This trick is why I’m not including Elemental Adept in the build. You don’t want to ignore your own resistance and explode yourself. Leave that to Wild Magic Sorcerers. We’ll grab Summon Undead for when our party needs an extra body.
7	New Invocation: – Repelling Blast Retrain Invocation: – Investment of the Chain Master -> Grasp of Hadar New Spell Known: – Wall of Fire	By this level, your familiar’s attacks are likely feeling less effective as their attack bonus gradually falls behind. The tactical need to strap Darkness to your familiar to have them fight on your behalf has probably also caused some problems, and, by now, your familiar has probably been destroyed a few times. But now is also a great time to change tactics, because we now have Wall of Fire. To maximize the benefits, you want to push enemies through the wall as often as possible, forcing them to either go through the wall again to rejoin the fight or to waste several turns waiting for it to go away while you kill their friends. The combination of Repelling Blast and Grasp of Hadar allows us to push and/or pull enemies through the wall when we hit them with Eldritch Blast. We get two shots, allowing us to reposition one enemy twice or to reposition two enemies once each. Remember that, when someone creates simultaneous effects, the creator of the effects chooses the order in which they occur, so you can push your target through the wall, then immediately pull them back to keep them where you can see and attack them. This doesn’t let you re-trigger the Wall of Fire damage in the same turn, but your allies may still want a chance to hit them.
8	Feat: Skill Expert – Cha 18 -> 19 – Prof: Intimidation – Expertise: Persuasion New Spell Known: – Shadow of Moil	To further improve our capabilities as the party’s Face, we’ll grab Skill Expert. This puts us behind the Fundamental Math temporarily, but we’re frequently attacking with advantage and we’re using very few save-or-suck spells, so we should be fine. When you can’t Fireball your problems and there isn’t a good way to bring Wall of Fire into the situation, turn on Shadow of Moil and start blasting.
9	New Invocation: – Voice of the Chain Master New Spell Known: – Hold Monster	Voice of the Chain Master turns our imp familiar into an even better scout. Between invisibility and flight it was already great at exploring on our behalf, but the ability to perceive through its senses means that we can take more direct command. Speaking through it also allows us to do tricky things like harassing enemies who recognize our voice or deliver messages when we’re too lazy to go find whoever we want to talk to. You might consider retraining Devil’s Sight since your familiar can see in magical darkness, but remember that your familiar has 10 hp, and their death would mean that you suddenly can’t see in magical darkness. That might be fine at this point, but think about it carefully.
10	Fiendish Resilience	We already have resistance to fire, so poison or slashing damage are your go-to options here.
11	Mystic Arcanum: Eyebite New Spell Known: – Any New Cantrip Known: – Mind Sliver	Eyebite is cruise control for an entire fight. If you have Summon Undead running, you can command your undead as a Bonus Action while you repeatedly put enemies to sleep or cause them to panic. Mind Sliver is here to impose a save penalty before we hit enemies with a save-or-suck. We get our third Eldritch Blast ray at this level. Shadow of Moil and Eldritch Blast remain a consistently effective combo. Finally, we get our third spell slot. Time to drop three Fireballs, then take a nap.
12	Feat: Fey Touched (Cha 19 -> 20) New Invocation: – Any	Fey Touched gets our Charisma to 20, lets us cast Misty Step Once per day, and lets us pick a 1st-level spell. Silvery Barbs is a fine choice, but Heroism might also be cool because you can use spell slots to cast it again, so you’re automatically upcasting it to 5th level and can target your whole party. Is it weird to have a fiend patron, but borrow magic from some fey? Yes, it certainly is. But we’ve got 20 Charisma and they can’t convince us to stop. We have an empty space for an invocation here. Choose whatever seems interesting. Misty Visions is a personal favorite of mine because illusions are so much fun.
13	Mystic Arcanum: Finger of Death New Spell Known: – Any	Finger of Death is not the Warlock’s best 7th-level spell. But saving a 7th-level spell to last-hit an enemy to get both a permanent zombie and temporary hit points from Dark One’s Blessing is an incredible flex.
14	Hurl Through Hell	Basically short-term banishment when you hit with an attack. You have three shots with Eldritch Blast, so pick someone who really needs a 1-round time out, boot them to the lower planes, then drop an inward-facing circular Wall of Fire around their space and watch them return to the world’s most terrifying sauna.
15	Mystic Arcanum: Dominate Monster New Spell Known: – Any New Invocation: – Chains of Carceri	Chains of Carceri only applies to three creature types, but they’re decently common at this level since beasts, humanoids, and most monstrosities have fallen off of the CR scale by now. For anything that you can’t hit with Chains of Carceri, there’s Dominate Monster.
16	Feat: Metamagic Adept – Careful Spell – Quicken Spell	We get exactly two Sorcery Points, so spend them wisely. We’re mostly here for Quickened Spell so that we can cast Mind Sliver, then hit our debuffed target with Finger of Death or Dominate Monster. Careful spell is for when you fireball the floor underneath you. Pass your save for half damage, halve it again for fire resistance. Your 5th-level fireballs deal 12d6 (avg. 42 normally, but 47.04 with Flames of Phlegethos), reducing your average damage to yourself to just 11.75. That’s not even enough to get through the temporary hit points from Dark One’s Blessing. If you manage to kill something with the Fireball, you get fresh temporary hp. Hot enough to kill, but your eyebrows aren’t even crispy.
17	Mystic Arcanum: True Polymorph New Spell Known: – Any	I like to cast True Polymorph in order to turn myself into a massive problem.
18	New Invocation: – Shroud of Shadow	Enter every situation invisible. Reveal your presence in the most dramatic way possible. Maybe with True Polymorph. Surprise dragon! Many high-CR creatures are also spellcasters, often including some of our best spells. Blue Abishai can cast Dominate Monster 3 times per day. Balors can cast Fireball at will. Dragons can’t cast spells, but their breath weapons might as well be fireballs. This is a great place to multiclass if you haven’t already. Two levels of Sorcerer for Font of Magic or two levels of Fighter for Action Surge will both do a lot for you.
19	Feat: Lucky New Spell Known: – Any	Lucky is perfect when you have everything else you need but still want to get even more awesome.
20	Eldritch Master	Literally always a disappointing capstone.