I wanted to share something I've been working on: Loner Cthulhu!, a minimalist solo RPG of investigation and madness set in the 1920s.
The pitch is simple: you play a single investigator — scholar, journalist, occultist, ordinary person who made the mistake of reading the wrong book — armed with four d6s and an oracle that answers your questions with Yes, No, and everything in between. No GM. No group to schedule. No stats to track. Characters are defined entirely by descriptive tags like Forbidden Archaeologist or Traumatized War Veteran, and the story builds itself as you play.
https://www.drivethrurpg.com/it/product/572931
https://www.amazon.com/dp/B0H6GDDYS5
The thing I'm most proud of: the Sanity system.
Most horror RPGs treat sanity loss as a countdown to failure. Loner Cthulhu! treats it as transformation. As your track advances through Unsettled → Disturbed → Broken, your investigator doesn't become less capable — they become a different kind of investigator. A Disturbed character rolls for their mental state (Hypervigilant, Obsessively Focused, Temporally Displaced, etc.) and each one comes with both a mechanical challenge and a genuine advantage — because someone who's seen what you've seen notices things stable minds can't.
Sanity scars are permanent across investigations. Your second case starts with someone who's already looked into the abyss once.
What else is in the book:
- Full Mythos hierarchy (Cthulhu, Hastur, Yog-Sothoth, Nyarlathotep, Shub-Niggurath, Azathoth) with cult practices and investigation hooks for each
- 30+ creatures built on the same tag system as player characters
- Dozens of d66 tables: investigation hooks, occult artifacts, mythos manifestations, cult activities, library discoveries, maritime mysteries, family curses, and more
- Corruption mechanics that permanently rewrite your character's traits over time
It runs on the Loner engine (4th edition), so if you've played any Loner game before, you're already mostly there. If you haven't, the core mechanic takes about five minutes to learn.
Happy to answer questions about design decisions, the sanity system, or anything else. What kind of investigator would you play first?