Tiefling Warlock Build Guide

Levels 1-4

At level 1, select the Fiend patron. The temporary hit points from Dark One's Blessing combined with your Tiefling fire resistance make you remarkably tanky for a backliner. Take Eldritch Blast and Hex immediately. At level 2, you must take the Agonizing Blast and Repelling Blast invocations. Don't take utility invocations yet; you need to establish your baseline DPR. At level 3, choose Pact of the Tome to grab Guidance and Find Familiar (via the Book of Ancient Secrets invocation). At level 4, take the Fey Touched feat. Choose +1 Charisma to reach 16, and select Silvery Barbs as your 1st-level spell. This gives you a free teleport and reaction spell without taxing your Pact Magic.

Levels 5-10

Level 5 is a massive power spike. Your Eldritch Blast now fires two beams, scaling your baseline spell DPR to 9. You also gain Darkness from your Fiendish Legacy. Swap an old invocation for Devil's Sight so you can cast your racial Darkness on your own staff and fire with constant advantage. At level 8, take the Infernal Constitution feat to bump your 13 Constitution to 14, boosting your concentration checks and adding Cold and Poison resistance to your innate Fire resistance. By level 10, your Fiendish Resilience feature allows you to pick a fourth damage resistance daily. You are now a fortress of damage mitigation.

Levels 11-16

At level 11, your Pact Magic slots upgrade to 5th-level, and you gain your first Mystic Arcanum. Take Mass Suggestion; it doesn't require concentration and can instantly end encounters. Your Eldritch Blast fires three beams now, pushing your spell DPR to 12.38. At level 12, use your ASI to push Charisma to 18. Take the Tomb of Levistus invocation at this tier; if you ever take a massive critical hit, you can entomb yourself in ice to survive, which synergizes perfectly with your backline blaster positioning. At level 16, cap your Charisma at 20.

Levels 17-20

At level 17, your Eldritch Blast hits its final form with four beams, pushing your spell DPR to 16.5 without resources. For your 9th-level Mystic Arcanum, select Foresight. Cast it on yourself at the start of the day for eight hours of advantage on all attacks and disadvantage on attacks against you. At level 19, take the Spell Sniper feat to ignore half and three-quarters cover. Level 20 grants Eldritch Master, allowing you to regain your Pact Magic slots in one minute—perfect for back-to-back boss fights in Tier 4 dungeons.

Cantrips

Eldritch Blast: Mandatory. This is your primary damage source. Minor Illusion: Excellent for creating heavy obscurement to hide behind in combat. Remember, you already have Thaumaturgy from your Tiefling traits, so skip taking it here.

Level 1-2 Spells

Hex: Essential in Tier 1 for adding 1d6 necrotic damage to every hit of Eldritch Blast. Armor of Agathys: Scales brilliantly with your Pact Magic slots. Do not take Hellish Rebuke—your Fiendish Legacy gives it to you for free at level 3, saving you a precious spell known.

Level 3-5 Spells

Fireball: The reason you take the Fiend patron. Hunger of Hadar: Drops a massive area of difficult terrain and blindless. Combine this with Repelling Blast to constantly push enemies back into the void. Synaptic Static: A psychic Fireball that targets Intelligence saves and debuffs enemy attacks without requiring concentration.

High-Level Spells

Mass Suggestion (6th): No concentration required, affects up to twelve creatures. Forcecage (7th): The best control spell in the game. Trap a melee boss, then laugh as you short rest. Foresight (9th): Eight hours of constant advantage on your four Eldritch Blast beams.

Fey Touched

Take this at level 4. With a starting Charisma of 15, this half-feat pushes you to 16 (+3 modifier). More importantly, it grants a free cast of Misty Step and a 1st-level Divination or Enchantment spell (take Silvery Barbs or Command). For a Warlock starved of spell slots, gaining two free casts a day is mathematically superior to a standard ASI.

Infernal Constitution

Take this at level 8. This Tiefling-exclusive feat bumps your 13 Constitution to 14, improving your HP and Concentration saves. It also grants resistance to Cold and Poison damage, and advantage on saving throws against being poisoned. Combined with your innate Fire resistance, you negate a massive portion of elemental damage in the Monster Manual.

Spell Sniper

Take this in Tier 3 or 4. As a blaster, enemies will constantly try to take cover from your Eldritch Blast volleys. Ignoring half and three-quarters cover ensures your DPR remains consistent, and doubling the range to 240 feet keeps you safely out of enemy spellcasting range.

Tier 1 (Levels 1-4)

Focus on acquiring Studded Leather Armor immediately to capitalize on your 14 Dexterity, netting you a 14 AC. Beg, borrow, or steal a Bloodwell Vial +1. It boosts your spell attack rolls and DCs, and lets you recover 5 Sorcery Points if you multiclass, but even pure Warlocks benefit heavily from the raw stat boost.

Tier 2 (Levels 5-10)

Seek out a Rod of the Pact Keeper +2. This is your holy grail, increasing your Eldritch Blast accuracy and allowing you to regain one Warlock spell slot as an action once per long rest. Pair this with a Cloak of Displacement to force disadvantage on attacks against you, protecting your fragile d8 hit die.

Tier 3 (Levels 11-16)

You want Illusionist's Bracers from the Guildmaster's Guide to Ravnica. These allow you to cast a cantrip as a bonus action if you cast it as an action. This literally doubles your Eldritch Blast output from three beams to six per turn, skyrocketing your DPR far beyond the projected 12.38.

Tier 4 (Levels 17-20)

Acquire a Robe of the Archmagi. It sets your base AC to 15 (pushing your total to 17 with your DEX), grants advantage on spell saving throws, and increases your spell attack bonus and save DC by 2. This stacks with your Rod of the Pact Keeper for absurd accuracy.

As a Blaster, your job is sustained ranged damage and battlefield control via forced movement (Repelling Blast). You need frontliners who can capitalize on the chaos you cause. Pair this build with an Oath of Conquest Paladin. You can cast your racial Darkness on their shield if they have Blind Fighting, or simply push enemies into their Aura of Conquest, trapping them in place.

You also heavily benefit from a Twilight Domain Cleric. Their Twilight Sanctuary grants a massive buffer of temporary hit points every round. Since your Tiefling Warlock only has 69 HP at level 11, that constant temp HP generation ensures you never drop concentration on your major spells like Hunger of Hadar or Hex.

Sorcerer 3 Dip

Taking 3 levels in Divine Soul or Clockwork Soul Sorcerer is an optimal detour after Warlock 5. It gives you the Shield and Absorb Elements spells, low-level slots to cast Hex without burning Pact Magic, and Metamagic. Quicken Spell allows you to cast Eldritch Blast as a bonus action for explosive burst damage.

Fighter 2 Dip

Starting Fighter 1 gives you CON save proficiency and medium armor/shields, jumping your AC to 19. Taking Fighter 2 gives you Action Surge. In a single turn, you can cast Fireball, Action Surge, and fire a full volley of Eldritch Blast. It delays your spell progression, but the burst damage is unparalleled.

• Wasting Spells Known on Innate Magic: Do not select Hellish Rebuke or Darkness when leveling up. Your Fiendish Legacy gives you both for free. Pick spells you can't get elsewhere.
• Ignoring Repelling Blast: Pushing a creature 10 feet per beam with no saving throw is arguably better than the damage from Agonizing Blast. Failing to take this invocation cripples your battlefield control.
• Standing in Melee: With 33 HP at level 5 and a melee DPR of just 3.9, you have no business holding a dagger. Use your 14 Dex to stay far away and rely on your 9 spell DPR.
• Forgetting Fire Resistance: Tieflings take half damage from fire inherently. Don't waste your Warlock Fiendish Resilience (at level 10) on Fire; pick Poison or Cold instead.