SotU Solo Rules Light Is Out — Here's What's Inside

In 2009, Nicolas Dessaux asked a simple question: if a one-line stat block is enough for a monster in a D&D module, why not for a player character? Searchers of the Unknown was born — a minimalist RPG that spawned dozens of hacks and became an OSR classic.

SotU Solo is a solo hack of that game. The idea: take that ultra-light philosophy and build a complete solo game around it. Not a clumsy adaptation of a multiplayer system — something designed from the ground up for one player.

The Rules Light version is available for free on DriveThruRPG. Here's what's in it.

What was already there (more or less)

Four old-school classes. Fighter, Thief, Wizard, Cleric. Each one fits in a few lines. Character creation takes five minutes.

A single resolution system. d20 + level + bonus ≥ target. One mechanic for everything: combat, exploration, saves. No subsystems to memorize.

Spell lists for Wizards and Clerics, levels 1 through 4.

What's new

The core rules come from SotU, but solo play raises specific problems the original system doesn't solve. How do you manage a group alone without drowning in character sheets? How do you keep combat from becoming a mindless loop of dice rolls? Two mechanics were designed to address this.

The Commander. You don't manage a party of four characters — you play one hero who recruits allies. Allies are not separate PCs with their own turns: they grant bonuses to the Commander's rolls and absorb damage in his place. A Lead Points system (equal to level + 1) controls group size. You recruit, sacrifice, replace — without ever opening a second character sheet. A full ally roster is included, from a simple torchbearer to a conjurer, including a scout who prevents surprise and a sergeant who buffs the entire squad.

The Sparrow Fighting Law. The problem with solo combat is repetition: I hit, it hits, I hit. Here, every two rounds, the environment shifts — slippery ground, thick fog, collapsing ceiling, spreading fire. Each shift imposes a passive effect on everyone (no ranged attacks in fog, -2 on slippery ground) and offers risky opportunities to the Commander alone: push an enemy into the void, trigger a targeted cave-in, vanish into a panicked crowd. Success gives a massive advantage. Failure costs dearly. Ten environmental contexts on a 1d10 table. Fights become tactical puzzles where every round presents a real choice: play it safe or go for the spectacular move.

Illustration from Kr0max

What I'd like to do next

This version is the game's engine. The rules, the Commander, combat. It's enough to play if you have an OSR module handy or some solo experience.

What I'm working on: hollow dungeons — locations with atmosphere, history and pre-connected rooms, but partially empty. The player fills them with the antagonist faction of their choice. The same dungeon played with goblins, undead or bandits yields three different experiences. Modular, replayable content.

And an adventure framework to structure your own quests: pick an antagonist, define an objective, identify the obstacles, and chain dungeons together without heavy prep.

The PDF (free)

SotU Solo builds on the work of Nicolas Dessaux, Simon J. Bull (SotU Refired), BDFiscus (Spellcasters of the Unknown) and the anonymous author of SotU D20 Style. These people shared their work freely. I'm doing the same.

Download SotU Solo Rules Light on DriveThruRPG — free PDF.

If you play it, I'd love to hear your feedback. This game is a work in progress and your sessions matter.