Need A Last-Minute Halloween One-Shot Adventure Idea?

Roleplaying Tips Newsletter #1133

I was chatting with new subscriber Ric Miller this week, and he inspired today’s tip that’ll help you prep and run an awesome Halloween adventure this weekend if you have not found one yet.

The tip is simple, yet full of amazing potential: Just add Cthulhu.

Flash Sale Alert

Before I jump into today’s tip, if you do still quest for a scary adventure this weekend, look no further than my just released 5 Room Dungeon Zine #1:The Tower of Drowned Shadows for D&D 5E.

Available in PDF and print, with full-scale printable and VTT png maps, this scary crawl will challenge even veteran players.

Imagine being trapped inside a submerged tower.

A dark secret with promise of great treasure lies at the very bottom. You must swim through lightless corridors and gruesome chambers filled with horrors and traps.

But the nightmare has only begun for your PCs who must also contend with two undead factions warring in the dark and hostile stone dungeon.

Shadows of loyal guards protecting the tower’s family, and specters of assassins questing for the disturbing cellar secret, fight in the soundless depths.

As this is a 5 Room Dungeon written by yours truly, it will be quick for you to read and prep for a game this weekend.

It includes designer notes where I explain my thoughts behind this adventure’s design, new monsters with instructions for scaling to 4th, 8th, and 12th level PCs, custom NPCs, and a new magic item – Frostfinger, a socketed blue blade.

The adventure supports murder hobos and roleplayers. Let your players decide how they’ll deal with the undeadly factions. Will they choose pike or parley?

You can purchase my adventure in digital and print format from DriveThruRPG.

But if you buy it directly from me this weekend, thus saving me in fees, I’ll pass along savings to you.

Flash Sale:

Get the PDF edition of The Tower of Drowned Shadows here for just $5, including the VTT maps and tokens.

“I DM Ghosts of Saltmarsh with a homebrew twist incorporating even more Lovecraftian components,” Ric shared with me.

That’s when the light bulb went off.

If stuck for a Halloween one-shot, why not take an adventure you’re run before and just add Cthulhu?

Or Stranger Things.

Or the Headless Horseman.

Or the Great Pumpkin.

You don’t even need to reskin the adventure.

Instead, change the tone via your GMing, and add a few ingredients.

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5 Quick Ways to Cthulhu-ify an Adventure

Add an Unspeakable Evil

Two choices here.

First is to replace the adventure’s villain with an ancient and dark evil that could destroy the world.

You can use the existing villain and simply make them corrupted, or you could swap in a new Big Bad Cthulhu monster entirely.

Second choice is to leave your villain as-is and add a Cthulhu creature in the background.

This creature could be the final obstacle after the villain.

Or you could run it as ambient terror, where it manifests in different encounters to challenge and frighten our poor heroes.

Add a Diabolical Ritual

Many adventures culminate in a confrontation with a villain.

For our horrific one-shot, we add an evil ritual to the scene.

This appends a deadline clock to your game, as well.

Look for special encounters leading up to the adventure finale. Make some of them clock ticks for the ritual’s countdown.

For example, in my adventure 5RDZ #1: The Tower of Drowned Shadows, you could have the specter assassins plotting a ritual in the cellar to finally reveal the ancient secret buried under the submerged dungeon and to defeat their hated enemies above, once and for all time.

The specters might be combing the tower looking for ritual ingredients – a simple Story Overlay to their actions.

Slay the specters. Stop the ritual. Save the world.

And get the treasure!

Add Darkness

Horror haunts harder at night.

Switch encounters to moonlit settings where possible.

Artificial darkness adds challenge to encounters, as well.

Even a total eclipse lasting a few minutes could form an epic finale in darkness during the battle with our Cthulhu villain.

Beyond physical darkness, add themes of spiritual darkness and corruption to your NPCs and scenes to further cast your adventure into cold and mind-numbing shadows.

Add Insanity

Give NPCs fears and flaws. And have them act accordingly to unsettle your players.

Twist environments into unnatural contortions.

Make the villain and their minions agents of insanity.

Add a Terrifying Dimension

A dark portal lets anything enter your adventure. Without a bouncer to keep the riffraff at bay, you can throw in all kinds of strange effects and terrifying monsters.

Cast the sky the colour of a dark bruise.

Sew the scent of a thousand graveyards into a cold wind that blows straight up the characters’ legs.

Rain down ash as silent sign something’s broken and suffering.

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What’s Your Favourite Adventure?

If you’re panicking because you’ve got a Halloween one-shot this weekend and have no idea about what to do, pull a beloved adventure off your shelf.

You already know the adventure’s details.

And even if players know the details too, the twists you’ll add will keep them guessing – and terrified. Just add Cthulhu.