I started work on another Warlock for Mythos Month, one that would serve as an “Essentials” rewrite of the PHB Warlock. I figured the class needed an archetype, since the Warlock tends to be all over the place in overall design.

While sifting through powers in the Player’s Handbook, I had something like an epiphany — I can’t rightly explain how the idea came to me — the Warlock isn’t an Arcane class. Not only does the Warlock fail to fit the mold of the only other Arcane class in the book, it fails to fit in with any of the other Arcane classes.

Looking at the Warlock, the Wizard, the Swordmage, the Artificer, the Bard, and the Sorcerer, you’d think the Arcane source threw its hands up in the air when it came to mechanical theming. Martial classes have armor and weapons, Divine classes have deities and domains, and Primal classes have spirits. What’s the Arcane theme?

If you drop the Warlock — or move it over to the Shadow classes — then a theme becomes more apparent. Arcane classes favor keywords and damage types. This is all true while the Warlock is still in the room. The elephant, is the Warlock’s theme.

Wizards pry loose the secrets of the multiverse for power. Artificers brew potions and craft items of power. Sorcerers derive power from their heritage. Bards draw power through the performance of songs and recitation of legends. Swordmages bind themselves to a single weapon, which becomes an extension of their powers.

The Warlock forges a pact with an otherworldly force.

See now, when you explain the source of their powers all together like that, it seems like the Warlock belongs with the rest, but the problem is that “forging a pact with an otherworldly force” is pretty much the Shadow magic source in a nutshell.

What I would posit then is — that rather than “pledging a portion of one’s soul to the Shadowfell,” as I believe the story goes with Shadow magic-users, that forging a pact with an (any) otherworldly power being the de facto Shadow magic theme.

And the Warlock is the star of the Shadow magic show.