https://parts-per-million.itch.io/players-guide-to-solo-roleplay

Using Cepheus Engine for Solo Play.

Solo roleplay is put forward as being for anyone who wants to play when there is no one else available. Most solo tools are actually built with the Game Master in mind. GMs are naturally more used to improvising entire scenes, creating NPCs on the spot, and having to grab random tables to create content on the fly. These are not normally player-facing tools and skills.

These solo tools add more support for players who may be less familiar with having to improvise everything. It supports world-building as an incremental process and challenges you with questions about the scenes and events to make you think about sights and sounds you may not have considered.

Solo is a perfect way to learn a new game, test your first adventures and going beyond just making characters when you are first getting to know the rules.

Your adventures are supported using a structure very similar to the adventure structure presented in the Cepheus SRD, but slightly modified, and a simple 2d6 oracle for asking questions and creating unexpected events.

A print version of these rules is available here.