Aren’t all Harry Potter characters wizards?

The Harry Potter D&D character build for House Slytherin presented in this article is a warlock. The Undead patron from Van RIchten’s Guide to Ravenloft is a natural choice for the House of Lord Voldemort. Our Slytherin warlock uses cunning, fear, and deception to pursue their own ambitions.

In the Harry Potter universe, all students at Hogwarts are called wizards and witches. But if we want to play a Harry Potter campaign in Dungeons & Dragons, we can use the classes of D&D to create D&D expressions of Harry Potter characters. (We have done something similar previously with the Suicide Squad D&D party).

The goal is to create a party of characters in the Harry Potter universe, which make for an interesting, diverse, and effective D&D party. The easiest way to do so, is to reskin other classes, in order to create D&D expressions of Harry Potter character archetypes.

The ground rules for Harry Potter D&D characters

The Harry-Potter-themed character build for a player character from House Slytherin below, and any other Hogwarts D&D characters in this series, start at character level 3. This is so they unlock features of their subclass, as well as the Spellcasting feature, if they have one. Even though these characters aren’t all wizards, they nonetheless are magical.

No race is specified for the Slytherin character build because there could be many different races in a D&D version of Hogwarts. We could play a Harry Potter D&D game with all humans, but we could also assume that in our version of Hogwarts, humans walk the hallways alongside elves, centaurs, goliaths, and many other races.

The Slytherin warlock

Or perhaps in Slytherin,
You’ll make your real friends,
Those cunning folk use any means,
To achieve their ends.
Sorting Hat

Slytherins embody cunning, resourcefulness, leadership, and ambition. This makes warlock a logical class choice for a Slytherin D&D character. A warlock uses otherworldly powers to advance their ambitions, often irrespective of the dangerous consequences.

Level 1 Slytherin warlock: the Undead patron, eldritch blast

At first level, we choose a patron for our Slytherin character, and we gain access to our core cantrip: eldritch blast. Here is how we can reskin these ability to make a Harry-Potter-themed D&D character:

The Undead patron. An undead remnant of a legendary Slytherin like the founder of the House, Salazar Slytherin, or his most feared heir, Tom Riddle, aka Lord Voldemort is our patron. This patron might speak to us, and ask as to perform nefarious deeds. But the relationship goes both ways. We gain power from the patron, but the patron needs us to enact their will in the world.
Form of Dread. We can take on aspects of our Slytherin patron to instill fear in our enemies. Maybe we grow pale, our nose recedes, and we take on serpentine features, like scales or slit pupils.
Eldritch Blast (cantrip). This cantrip can be a mechanical stand-in for many dark offensive spells which our patron taught us. We point our wand and a beam of energy races towards our target.

Level 2 Slytherin warlock: power and deception

At second level our Slytherin D&D character improves their offensive spellcasting and their cunning deceptions. Both thanks to these two eldritch invocations:

Agonizing Blast. Adding our Charisma modifier to eldritch blast makes us hit that much harder with our wand attacks.
Mask of Many Faces. Our patron values cunning and deception just as much as raw power, so he shows us the secrets of changing our appearance to fit the needs of our current ambition.

Level 3 Slytherin warlock: Nagini comes

At level three, we gain a trusted serpentine companion. Slytherins have an affinity towards snakes and the most powerful wizards of the House are able to speak Parseltongue, the language of snakes. At this level, we bind a magical snake to our service through the pact boon, Pact of the Chain.

Pact of the Chain. Our Slytherin D&D character gains a magical ally. We summon a snake, perhaps a descendant of the legendary Nagini, familiar of Lord Voldemort. Mechanically, we can use the imp stat block with its powerful invisibility feature. We can reskin the sting attack to be a bite.

Level 3 Slytherin warlock spell selection

The following spells fit well with the theme of cunning, resourcefulness, leadership, and ambition. Here is the list along with tips on reskinning the spells to fit a Harry Potter D&D game. Keep in mind that thanks to Pact Magic, all our spells will be cast at second level, and therefore target more creatures (in the case of bane), or deal more damage.

Eldritch Blast (cantrip). This is our bread-and-butter offensive spell. We can flavor each instance differently by changing the appearance of the beam of energy, and the incantation we speak to summon it.
Minor Illusion (cantrip). Slytherins use subterfuge. This spell allows us to use cunning trickery with the aid of magical illusions.
Arms of Hadar (1st level). With this spell we can surround ourself with magical serpents which lash out at enemies attacking us.
Bane (1st level). A dark curse is just the thing a Slytherin would throw at enemies. Bane will make it less likely for enemies to succeed against our Form of Dread, making it that much easier to frighten them.
Blindness/Deafness (2nd level). Another resourceful spell as it reliably disables enemies without requiring our concentration.
Suggestion (2nd level). This is a simple version of the Imperius Curse, allowing us to mind control an enemy for 8 hours.

Links & Resources

Harry Potter Wiki: “Slytherin” – https://harrypotter.fandom.com/wiki/Slytherin
Slytherin Warlock build on D&D Beyond – https://ddb.ac/characters/88775907/Q8YDJt (Note that this character uses the variant human race to gain another eldritch invocation: Eldritch Sight. This allows us to see through a darkness spell, gaining advantage on our eldritch blast attack rolls, when we are obscured by magical darkness.)