Warlock 101: The Fiend

Class is back in session, and it’s time for your warlock to make some new friends. Er, fiends. Well, one fiend in particular: The Fiend. Warlocks are magic-users who gain access to tremendous arcane power by making a pact with an otherworldly being that needs pawns in the mortal realm. This power is incredible, but has a few interesting and unusual drawbacks. Warlocks are so different from other spellcasting classes, that it’s best to forget everything you know and start from scratch. Activate your beginner’s mind and take a look at how you can make the most of your Pact Magic.

Story of the Fiend

“It’s not fair!” shouted the young woman, shoving her parchment and books off of her desk in one fluid, furious motion. Rage flushed her face, and tears welled in her eyes as a sob crawled its way out of her throat. She fell back against her chair, limbs hanging loosely as tears fell freely, loosened by that first sob of anger. The droplets spattered against the papers strewn about her floor, smearing the ink of a half dozen failed tests. Conjuration. Divination. Abjuration. Enchantment. Transmutation. Even evocation, the subject that everyone around her had laughed about the ease in which they’d mastered their cantrips.

“I worked so hard,” she thought, between tears. “Twice as hard as them. Twice as long. They don’t deserve it—how easily it comes to them.”

She lunged forward, almost involuntarily, and slammed her firsts against the desk. The only object left on its hardwood surface was a candle in a stubby brass candlestick. It rattled as she stuck the desk—and when it settled, it was alight with a tiny orange flame. She buried her head in her hands for a few minutes more, crying until her tears were dry. Then she jolted upright with a gasp of pain. A trickle of crimson wax had rolled down the candle and along the lacquered surface until it reached her fingertips. She stared at the tiny flame through puffy red eyes, ten thousand tiny thoughts running through her rage-drunk mind.

“Did—did I do that?” she muttered aloud. A tiny voice within her said, yes. You did. She paused, still staring at the tiny flame, not even considering that the voice wasn’t her own. Then an idea struck her. She snatched a tear-stained page from the ground and held it in her hand. She glanced from the tiny flame to the paper, and imagined it aflame.


She tried again.


She clenched her jaw, feeling grief well up within her once more, when the voice returned. Don’t despair. Your power is different from theirs. Reach out and touch it. Something else welled within her—not grief, but a gift. A warmth, a flickering flame, a smell of sulfur. And the paper caught alight. She gasped, and smiled, and unbidden tears streamed down her cheeks. The flame danced upon the pupils of her eyes. Will you accept this gift? asked the voice?

“Yes,” gasped the warlock, unknowing of just what she had agreed to.

Otherworldly Patron: The Fiend Features

The Fiend is the most iconic warlock patron. Like Faust and Mephistopheles, you have made a bargain with being of the Lower Planes. It could be the D&D Archdevil known as Mephistopheles, or any number of Archdevils or Demon Lords—or even their lesser subordinates. It doesn’t even have to be an intentional pact; in the Brimstone Angels novels by Erin M. Evans, the young tiefling Farideh unintentionally makes a pact with a cambion named Lorcan, and finds herself pulled into a multiplanar game of cat-and-mouse with forces as great as Asmodeus himself.

Warlocks gain their Otherworldly Patron at 1st level, in stark contrast with almost all other classes in D&D, who gain their subclasses at 2nd or 3rd level. They gain four subclass features at 1st, 6th, 10th, and 14th level. You can read all of the Fiend features for free in the D&D Basic Rules. In summary, your subclass features allow you to:

  • Gain access to an expanded list of spells to learn from
  • Gain temporary hit points whenever you defeat a hostile creature
  • Call upon your fiendish patron to alter fate in your favor
  • Choose a damage type to resist whenever you complete a short rest, though magical or silvered weapons cuts through this resistance
  • Hurl a creature through hell, wracking their minds with supernatural evil

Benefits of the Fiend Patron

Making a pact with the Fiend allows you to be an incredibly versatile warlock. The warlock class allows you to refine your pact at 3rd level, giving you the option to become a weapon-wielding Pact of the Blade warlock, a spell-slinging Pact of the Tome warlock, or a familiar-summoning Pact of the Chain warlock. The Fiend patron synergizes well with all three of these pacts, giving you features that come in handy no matter what kind of pact you decide to make with your patron.

The Fiend leans slightly towards promoting a damage-focused, spell-using warlock, but it really lends itself well to all types of warlocks, meaning that the Fiend is an excellent patron for new warlock players, who aren’t quite sure what they want their character to do—or who just want an escape hatch in case they decide their current “build” isn’t working out. Other warlock patrons, like the Archfey or the Hexblade are more focused, making it harder to experiment or change your mind later on.

Drawbacks of the Fiend Patron

The warlock is an incredibly idiosyncratic class. Anyone who plays warlock after playing another spellcasting class will find that the biggest challenge to playing a warlock will be unlearning everything you know about playing a spellcaster—because warlocks function almost completely differently. Warlocks only have a tiny amount of spell slots, but they’re replenished after a short rest rather than after a long rest like all other spellcasting classes. This isn’t a drawback of either the warlock class or the Fiend patron, but players who approach a warlock like they’re just a weird wizard won’t have as much fun as those who come to the class completely free of comparison.

As for the Fiend patron itself, its greatest strength is also its greatest weakness. Versatility is an incredible thing, but not being able to specialize or find a niche within your party can be a problem. Even with this drawback, warlocks are incredibly good at dealing damage from afar, and the Fiend patron supports this niche well enough, even if it’s not quite as focused in its role as some other Otherworldly Patrons.

Suggested Build

If you’re playing a Fiend patron warlock from 1st level, you should choose a race that gives you a bonus to your Charisma score. The tiefling Farideh is the iconic fiendish warlock, and the bonus to Charisma that tieflings gain, as well as their racial spells, make them excellent warlocks. By the same token, dark elves gain a bonus to Dexterity and Charisma, and have innate spells as well. Dragonborn is an interesting racial choice for a warlock thanks to their innate bonus to Strength, especially if you decide to choose the Pact of the Blade later on.

Once you’ve placed Charisma as your highest ability score, consider what else is important to you. If you want to fight with sword and shield or a two-handed weapon, Strength might be the second most important ability for you. On the other hand, prioritizing Dexterity would make you a terror with a rapier. Constitution will also help you take more blows in combat, and hang onto your precious concentration spells more easily (more on them later). Wisdom and Intelligence aren’t useless for you, but they’re far from a secondary or even a tertiary ability.

Selecting EQUIPMENT when creating your warlock is a good idea; a simple weapon of your choice, like a dagger or a quarterstaff, is useful. Your choice of arcane focus or spell component pouch is entire aesthetic, and a dungeoneer’s pack will almost always be more useful than a scholar’s pack. A few more daggers, some leather armor, and another simple weapon of your choice helps round out your arsenal. You can wear light armor, so hunting for a set of studded leather later in your adventuring career might be useful.


Warlocks don’t have the Spellcasting trait like most other spellcasters. Instead, they have Pact Magic. You start at 1st level knowing two cantrips, two 1st-level spells, and only a single spell slot. But that spell slot is recovered whenever you take a short rest; you could hypothetically cast spells all day long, as long as you have a little catnap in-between castings. Also of note is that your spell slots are all of the highest level you can cast (see the “Slot Level” column on your class features table). This isn’t useful now, but having your spells automatically scale to their highest possible power level is an incredible feeling.

Since you only have one spell slot for now, you need to make it count. You get a second slot at 2nd level, which is nice, but you don’t get your third spell slot until 11th level! Fortunately, you get the most powerful damaging cantrip in the game, eldritch blast, so you’re never useless, even when you’re out of spell slots.

You can learn any two 1st-level spells from the warlock spell list—which includes the 1st-level spells on your “Fiend Expanded Spells” list. You’ll want to choose these spells carefully; since the number of spells you know is severely limited, you want to have a versatile spell list. As you go on adventures and learn what dangers your character tends to face, you can personalize your spell loadout. Try to choose one spell labeled OFFENSE, and one labeled either DEFENSE or SUPPORT. Note that this list only includes some spells from the Player's Handbook, so if you want to choose more unusual spells, or have other sources like Xanathar's Guide to Everything, you'll have to do a little self-directed research. This list is just here to get you started if this is your first time playing a Fiend patron warlock.

Especially at lower levels, a warlock will want to have spells that last for a long time. Since you have so few spell slots, maintaining concentration on spells with lasting effects is much more efficient than simply firing off a single explosive spell. It’s for this reason that hex is one of the mightiest warlock spells in the game, if you want to deal massive damage, that is. While hanging onto concentration for this spell, a hexed creature takes an additional 1d6 damage every time it’s hit. And you can concentrate on the spell even if a creature isn’t currently hexed, allowing you to essentially carry the spell between combat encounters—as long as its duration doesn’t expire.

You also get to choose two cantrips that you’ll know forever. Unless you want to play an unusual type of warlock, eldritch blast is far and away the best choice. It’s one of the backbones of your class. Your other cantrip is up to you, and is a good way to add personality to your character.

Eldritch Invocations

Once you reach 2nd level, you gain the ability to select two Eldritch Invocations. You can trade out an old invocation for a new one whenever you gain a level in this class, and you gain brand-new invocations every two or three levels (again, see the warlock class features table). Some invocations have prerequisites that you must meet in order to select them, so learning how to trade out old invocations for this fresh and exciting ones is an important skill to master. Here are some invocations that will probably be useful to you as a warlock of the Fiend:

Agonizing Blast. You deal additional damage with your eldritch blast, what’s not to like? Note that as you level up and your eldritch blast fires multiple beams, each one of these beams benefits from this additional damage. That’s amazing!

Armor of Shadows. If you take this invocation, your AC will almost always be 13 + your Dexterity modifier. This is great if you find that enemies are ganging up on you.

Beguiling Influence. If your campaign has a lot of intrigue—or even if just the current arc of your campaign is roleplay-heavy—then this invocation will make you a silver-tongued charmer.

Book of Ancient Secrets. This invocation is only useful to Pact of the Tome warlocks (a choice you can make at 3rd level), but it’s incredibly useful. Since you don’t have the Ritual Casting feature that many other spellcasting classes have, this is the only way to cast ritual spells as a warlock. It’s incredibly powerful.

Devil’s Sight. If you have the power to cast darkness, such as through your tiefling or drow innate magic, this invocation can really ruin your enemies’ day.

Mask of Many Faces. Like Beguiling Influence, this invocation is great for campaigns that lay the intrigue on hot and heavy. Situational, but powerful within its niche.

Thirsting Blade. Like Book of Ancient Secrets, this invocation is only useful for one type of warlock: Pact of the Blade. However, if you have followed that path, it’s invaluable. Regrettably, it’s only available once you reach 5th level.

There are lots more useful invocations in both the Player’s Handbook and Xanathar’s Guide to Everything, but many of them are only available to you as you gain additional levels. Play around and find out what you like; don’t forget that you can always swap out a lackluster invocation when you gain a warlock level.

Voice of the Chain Master. The Pact of the Chain can be incredibly powerful, if you have the tactical inclination to micromanage both your character and your familiar. This invocation just makes that power greater.


You want to make your Charisma as high as you can, so that creatures can’t resist your saving throws and spoil one of your precious spell slots. However, once your Charisma is at least 18, it might be worth taking a feat instead of an Ability Score Increase. There aren’t a lot of feats that you’re desperate for (fortunately), but some interesting ones are:

Elemental Adept (Fire). As a Fiend patron warlock, you’ve got a lot of firepower at your fingertips. Making it easier to hurt monsters with that fire is sweet.

Inspiring Leader. This is a fascinating character choice, and could turn you into something of a cult leader.

Resilient (Constitution). Hanging onto concentration is vitally useful, since you have so few spell slots. Being better at all Constitution saving throws is a nice bonus, too.

War Caster. If you’re going a Pact of the Blade route, this is all but essential. Concentration is so invaluable to you, it’s probably worth taking even if you don’t plan on wading into melee combat.

At Higher Levels

Warlocks become very interesting as they reach higher levels. The finer points of spell scaling and Mystic Arcanum are beyond the scope of this guide, but read their entry in the Player’s Handbook or the Basic Rules. As you gain levels, you really start to diverge from the way other spellcasters play.

If you want more advice for building a warlock, check out Warlock 101. Have you ever played a Fiend patron warlock? What advice would you give to players that want to make a character like this?

James Haeck is the lead writer for D&D Beyond, the co-author of  Waterdeep: Dragon Heist and the Critical Role Tal'Dorei Campaign Setting, the DM of  Worlds Apartand a freelance writer for Wizards of the Coast, the D&D Adventurers League, and Kobold Press. He lives in Seattle, Washington with his partner Hannah and their animal companions Mei and Marzipan. You can find him wasting time on Twitter at @jamesjhaeck.


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