Best Warlock Build in BG3 — Fiend Patron Complete Guide

Warlock Build at a Glance

Why Fiend Patron is BG3's Strongest Warlock Subclass

The Fiend patron provides the most combat-relevant features of the three Warlock patrons in BG3 (Fiend, Great Old One, The Archfey). Dark One's Blessing gives you temporary hit points equal to your CHA modifier + Warlock level every time you kill a creature — at CHA 20 and Warlock 7, that is 12 THP per kill, refreshing constantly in fights against groups. These THP stack with your actual HP, effectively giving you a buffer that absorbs the first hits of every encounter.

The Fiend's expanded spell list adds Burning Hands (Lv1), Command (Lv1), Blindness/Deafness (Lv2), Scorching Ray (Lv2), Fireball (Lv3), Stinking Cloud (Lv3), Fire Shield (Lv4), and Wall of Fire (Lv4) to your prepared spells — all free without using your limited Warlock known spells slots. Fireball at 3rd level for a Warlock (who only has 3rd-level pact slots) deals the same damage as for any other caster but recovers on short rest, meaning you can cast Fireball twice per short rest in critical moments.

At high level, Fiend Warlocks gain Dark One's Own Luck (add 1d10 to an ability check or save once per short rest) at level 6 and Fiend Resilience (resistance to one damage type per short rest — choose fire or cold based on the encounter) at level 10. These passive defenses combine with Dark One's Blessing's THP to make the Fiend Warlock the most self-sufficient of the three subclasses.

The Great Old One subclass offers Telepathy and mind-control spell additions — thematically interesting but mechanically weaker. The Archfey subclass adds Fey Presence (fear/charm in an AoE) and Misty Escape (teleport when hit) — situationally powerful but inconsistent. Fiend delivers reliable combat value every single fight.

Eldritch Blast — Your Main Attack at All Levels

Eldritch Blast is the Warlock's bread-and-butter cantrip and scales with character level — at level 5 you fire 2 beams per cast (each dealing 1d10 force damage), and at level 11 you fire 3 beams. Each beam can independently hit or miss, and each beam can trigger its own invocation effects. This is critical for understanding Repelling Blast: if all 3 beams hit at level 11, you can push the target 4.5m three times, totaling 13.5m of forced movement in one cast.

Agonizing Blast (invocation, available at Warlock 2) adds your CHA modifier to the damage of each Eldritch Blast beam. At CHA 20, that is +5 damage per beam, per hit. With 3 beams at level 11, Agonizing Blast alone adds +15 damage to a full-hit Eldritch Blast. This invocation is mandatory for the caster build and should be taken as soon as it becomes available at level 2.

Repelling Blast (invocation, level 2) pushes targets 4.5 meters on each beam hit. The force push in BG3 functions as genuine forced movement — it bypasses freedom of movement, pushes enemies off ledges, sends targets through Spike Growth or Hunger of Hadar, and creates space between enemies and your backline. In the Spike Growth combo with a Druid ally, every Repelling Blast push forces the target through 4.5m of spiky terrain for 2d4 per 5 feet — often 4d4 per beam. This is one of the highest-damage-per-beam interactions in the game.

At level 11 with Agonizing Blast (CHA 20), each full Eldritch Blast that hits all 3 beams deals 3d10+15 force damage — average of 31.5 damage with no spell slot expenditure, as a cantrip. This is why the Warlock's zero-resource damage floor is among the highest of any class in BG3.

Pact Magic — Short Rest Recovery and Slot Economy

The Warlock's Pact Magic slots (the short-rest-recovery spell slots) are fundamentally different from full caster slots. A Warlock has only 2 spell slots at level 1, scaling to 3 at level 11 and staying at 3 until Warlock 17 (beyond BG3's level 12 cap). However, these slots always scale to your highest available level — at Warlock 9, your 3 slots are all 5th-level slots. This means every Warlock spell is cast at maximum power available.

In BG3, each long rest allows 2 short rests (pressing the short rest button at camp). This means Warlocks recover their slots 2 additional times per day for free, effectively tripling their daily resource count compared to a reading of just long-rest recovery. A Warlock 9 with 3 slots effectively has 9 effective 5th-level slots per long rest. This is extremely competitive with full casters' slot count, especially for spells like Hunger of Hadar, Hypnotic Pattern, and Banishment that are worth casting at 5th level.

The slot economy changes when you take the Padlock multiclass (Paladin 5 / Warlock 7). In this build, Warlock Pact Magic slots (2 at level Warlock 4) are used to fuel Paladin Divine Smite — this is legal because Divine Smite only requires any spell slot, not specifically Paladin slots. The result: Warlock slot recovery on short rest means you can smite 4+ times per long rest (2 slots × 2 short rests = 6 smite opportunities, minus any slots spent on spells). The Padlock is one of the highest burst-damage builds in the game because of this synergy.

For the pure caster Warlock, the key decision each combat is: spend slots on high-impact spells (Hunger of Hadar, Hypnotic Pattern) that end or cripple the fight, or save them for the next encounter knowing short rests restore them. In practice, always spend at least one slot per major fight — holding back conserves nothing if you short rest between fights anyway.

Level 1–12 Progression Table (Pure Fiend Warlock)

The Padlock Build — Paladin 5 / Warlock 7

The Padlock is one of BG3's most legendary multiclass builds, combining Paladin's Divine Smite burst damage with Warlock's short-rest Pact Magic slot recovery. The principle: Paladin Divine Smite requires any spell slot (not specifically Paladin slots), and Warlock Pact Magic slots recover on short rest. By using Warlock slots to fuel Smites, you effectively smite far more often than a pure Paladin can.

The level split that maximizes the build is Paladin 5 / Warlock 7. Paladin 5 provides Extra Attack (crucial — Smite only triggers when you successfully attack, so more attacks mean more Smite opportunities), Aura of Protection at Paladin 6 (+CHA to all saves for nearby allies — at CHA 20, that's +5 to every saving throw your party makes), and the base Smite damage progression. Warlock 7 provides 2 Pact Magic slots at 4th level (the highest available before you'd need more Warlock levels), Fiend's Resilience, and the key invocations.

Stat setup for Padlock: CHA 17 at creation, STR 14 (for melee attack rolls — Pact of the Blade can use CHA for attack/damage rolls via the Lifedrinker invocation, though you need Warlock 12 for that in a pure build; for Padlock at Warlock 7, use STR for weapon attacks and boost it), CON 14. Alternatively, if you use Pact of the Blade without Lifedrinker, take STR 16 and rely on a weapon with Str-based damage.

In practice: open each fight by casting Hex (Bonus Action — doesn't cost a Warlock slot if cast as Bonus Action at Warlock 1, but does cost a slot at higher levels when it's a regular spell), then attack with Pact of the Blade weapon. On any critical hit (rolled 20), immediately Divine Smite with the highest available Warlock slot (2d8+1d8 per additional level up to 5th level slot = 6d8 = average 27 radiant on a crit). With Elven Accuracy racial feature (if Half-Elf), triple-advantage raises crit chance dramatically, making the Smite-on-crit loop happen multiple times per fight.

Warlock Invocation Priorities

Best Races for Warlock

Drow (Dark Elf) is the strongest thematic and mechanical choice for Warlock. Drow get Faerie Fire (Advantage for allies on a failed DEX save), Dancing Lights (dim light manipulation), and Darkness (magical darkness — if combined with Devil's Sight invocation, Drow Warlocks can see through their own Darkness while enemies inside it are blinded). Superior Darkvision (120 ft) extends the effective range of One with Shadows invocation in dark environments. Drow also have natural CHA bonuses in some stat configurations. The Darkness + Devil's Sight combo is one of BG3's most powerful self-contained damage builds.

Half-Elf (specifically High Half-Elf or Wood Half-Elf) is the most versatile choice. High Half-Elf grants a free Wizard cantrip (take Booming Blade or Poison Spray for Padlock builds, or Fire Bolt for caster builds). Crucially, some Half-Elf configurations in BG3 grant the Elven Accuracy trait, which turns advantage into triple-advantage on attack rolls — tripling your crit chance, which is fundamental to the Padlock Divine Smite loop. Half-Elf also grants Darkvision and Fey Ancestry (Advantage against Charmed).

Tiefling (Asmodeus or Zariel lineage) is a strong option for pure caster Warlocks. Asmodeus Tieflings get Hellish Rebuke (2d10 fire reaction damage when hit) and Darkness as innate spells, plus bonus fire cantrips. Zariel Tieflings get Searing Smite and Branding Smite as racial spells plus Thaumaturgy and Produce Flame. The fire-themed abilities synergize well with the Fiend patron's fire-heavy expanded spell list.

Githyanki is unconventional but viable for Padlock builds — Astral Knowledge (proficiency in any skill for one long rest) provides skill flexibility, and innate Misty Step (at level 5) is genuinely useful for the melee Padlock. The Githyanki's STR racial tendencies also fit the STR-based Padlock melee build.

Recommended Starting Stats (Pure Warlock)

Feat Choices and Alternatives

Hunger of Hadar — The Warlock's Signature Spell

Hunger of Hadar (3rd level, Concentration) creates a sphere of darkness and tentacles that deals 2d6 cold damage to all creatures that start their turn inside it and 2d6 acid damage to all creatures that end their turn inside it. The sphere also creates difficult terrain, Blinds creatures inside it, and triggers Repelling Blast pushes further into it on Eldritch Blast hits at the sphere's edge.

The optimal Hunger of Hadar deployment is in a doorway, corridor, or room entrance — any chokepoint where enemies must pass through to reach your party. Once placed, enemies have three choices: move through the sphere (taking 4d6 per round), stay put and wait (taking 2d6 per round), or find an alternate route. Combined with Repelling Blast on any enemy at the sphere's edge (pushing them back in for another 2d6 acid), Hunger of Hadar effectively removes multiple enemies from combat for several rounds at the cost of one 3rd-level slot.

Hunger of Hadar does not damage your undead allies (if you're playing alongside Minthara) and does not affect creatures that are already inside — only those that enter or end their turn there. The sphere has a fixed position and cannot be moved. Upcast at 5th level, the damage increases but the positioning logic remains the same.

The one critical weakness: Hunger of Hadar requires Concentration, which conflicts with Hex. In most fights, use one or the other — Hex for single-target fights (boss encounters) and Hunger of Hadar for multi-enemy encounters (groups). With Dark One's Own Luck you can add 1d10 to a Concentration save in a critical moment, helping you protect the spell if it's about to break.

Equipment Progression — Act 1

Equipment Progression — Act 2

Equipment — Act 3 Best in Slot

Party Synergy — Who Pairs Well with a Warlock PC

A Warlock PC pairs best with a melee frontliner who can use Repelling Blast's push to create tactical positioning. Lae'zel (Fighter) trips enemies prone, Karlach (Barbarian) tanks damage in front — while the Warlock pushes dangerous enemies away from the frontline and into Hunger of Hadar zones. The Warlock keeps the battlefield manageable while martials do the melee work.

Jaheira (Druid with Spike Growth) is the best synergy companion for a Repelling Blast Warlock. Place Spike Growth in a corridor, then Repelling Blast to push enemies 4.5m through the spikes per beam. Three beams at level 11 can push an enemy 13.5m through 2d4 per 5 feet of spikes — dealing up to 6×2d4 piercing damage purely from the push. This combo requires almost no action economy investment beyond the initial Spike Growth cast.

A second caster (Gale or Shadowheart) provides the healing and utility spells that the Warlock lacks — Warlock known spells are limited (6 at Warlock 9) and spending them on utility reduces damage options. Let a full caster handle Revivify, Remove Curse, and Dispel Magic while the Warlock focuses on Hunger of Hadar, Hypnotic Pattern, and Banishment for fight-ending control.

The Warlock PC excels as the party's face character (Persuasion, Deception, Intimidation from CHA) and should lead social encounters. With Beguiling Influence invocation, the Warlock covers Deception and Persuasion with proficiency even without the skill background choices.

Common Mistakes When Playing Warlock

• Not taking Agonizing Blast at level 2: Some players explore other invocations (Armor of Shadows, Eldritch Spear) before Agonizing Blast. This is a significant DPS loss — Agonizing Blast's +CHA per beam applies every cantrip cast for the rest of the game. It is mandatory and should be your first invocation pick at level 2, before any other choice.
• Burning all Pact Magic slots before short resting: Warlocks recover slots on short rest, not long rest. Players who dump all slots into Hunger of Hadar in the first fight and then don't short rest before the next fight play the class inefficiently. After any meaningful fight, short rest immediately. With 2 short rests per long rest, this triples your daily slot economy.
• Confusing Pact Magic slots with full caster slots: Warlock Pact Magic slots always scale to the highest level available, but there are only 2 (or 3 at level 11+). Budgeting Warlock spell slots like Wizard spell slots (many slots, different levels) leads to running out early and relying on only cantrips. Plan to use 1–2 slots per fight and short rest between fights.
• Ignoring Hex: Hex is a Bonus Action to apply and adds +1d6 to every attack against the target. At level 5, when you fire 2 beams per Eldritch Blast and attack twice per action, Hex adds +2d6 per cast (2 beams, each independently rolls Hex). Players who forget Hex or don't reapply it when the target dies miss 10+ average damage per round for free.
• Not using Repelling Blast tactically: Repelling Blast's push is one of the most powerful positioning tools in the game. Players who take the invocation but just use it to push enemies away arbitrarily miss the value. Push enemies off ledges for fall damage, push enemies through Spike Growth, push enemies into the center of Hunger of Hadar, push enemies away from your downed allies. Each push is a free displacement of 4.5m per beam.
• Taking War Caster too late: Some players delay War Caster until level 8, taking an ASI at level 4 instead. Without War Caster, Hunger of Hadar and Hex break frequently under heavy attack pressure in Acts 1 and 2. The ASI can wait — War Caster protects your core combat loop immediately and should be taken at the first feat opportunity (level 4).
• Underusing Fiend Resilience: At Warlock 10, Fiend Resilience lets you choose a damage resistance once per short rest. Many players pick fire by default and forget to change it. Before entering a fight with heavy lightning, cold, or necrotic damage (Ice Storm boss, necromancer dungeon), switch Resilience to the relevant type. This is a free 50% damage reduction on a source type — use it actively, not passively.
• Forgetting that Hunger of Hadar blinds creatures inside: Blinded creatures have Disadvantage on attack rolls and targets have Advantage against them. Any creature stuck in Hunger of Hadar is effectively half-blinded. Combined with the difficult terrain, creatures in the sphere are spending their actions at Disadvantage and taking 4d6 per round just by staying put. The total value of this spell per cast is often 3–5x the spell slot's face value.