Miasma

“For decades, Londoners fed the Thames the vilest ingredients they could get their grubby hands on: rotting carcasses, gallons of human filth, and the remains of animals. Things so foul, even witches wouldn’t dare use them in their nastiest brews. In the end, they had brewed a concoction so evil the earth itself spat up the soiled river. Viscous waves of putrid sludge poured through London’s alleyways. Iridescent gases choked the air. Sickness and disease took form, The Great Stink. In panic, the city launched an emergency effort to seal away the horrors beneath a new sewer system of brick and concrete.

But concrete crumbles. And through the cracks... oozes MIASMA.”

It’s now 50 years later and the evil, once sealed away, wants it’s revenge. The royal court has chosen you as it’s soldier. Your task: Rid the sewers of the monsters residing there and receive a glorious reward*.

Miasma is a solo dungeon-crawling card game of grimy survival, nerve-testing encounters, and strategic risk-taking, set in the foul underbelly of Victorian London. You are an ill-equipped scavenger navigating a shifting maze of sewers. Each turn, you’ll explore face-down cards to reveal new rooms, spend precious stamina to push deeper, and manage your growing panic as you edge toward inevitable encounters with the city’s twisted denizens. Combat is a tense mini-game of tactical card play, reading suits, colours, and values to parry, absorb, or counter attacks while keeping an eye on your dwindling resources.

Every run is unique: procedurally generated dungeons, varied character abilities, questionable events, and unpredictable enemy behaviour ensure no two games smell the same. Will you risk the dangerous shortcut for a chance at treasure? Bargain with shady merchants for gear you can’t afford? Or keep your head down and pray the miasma doesn’t find you first?

The goal of this game is to defeat the boss lurking in the dungeon and survive what is thrown at you in the process. The rules are separated into three main parts: character creation, dungeon exploration and combat.

For a playthrough you’ll need:
-The ‘miasma rulebook’
-Several dice (D3, D4, D6, D8, D10, D20)
-2 decks of playing cards that have different backs for ease of play
-A ‘miasma character sheet’ alongside something to write with
(All files needed included and downloadable)

*A week’s worth of pay and a brooch of appreciation.

!This a playtest version of the game, containing all needed rules for a game of 'Miasma'. Note that artwork is not yet included into the rules PDF. The final commercial edition will contain revised rules, additional content, and artwork. This playtest edition is not representative of the final product. If you wan't to see this project finished and at it's full potentital, consider leaving valuable feedback and a donation!

License: This playtest is free for personal use and sharing in its unmodified form. No commercial use or alterations are allowed without permission. © 2025 Lars Eneman.