The Kingdom of Prester John by Frederic Walker

A solo journaling RPG of wandering between the reality of the late 1100s and the dreamscapes of medieval Christian mythology

In The Kingdom of Prester John, the player takes on the role of a member of the Christian clergy, departing Rome in 1177 on the pope's orders, in search of the Kingdom of Prester John, a godly, Christian king said to dwell somewhere far beyond the bounds of Christendom. 

The Kingdom of Prester John is played using a d10, which guides the writing of a journal of the player's travels. With each region the player travels to, their spiritual or temporal conviction increases, affected by both their travelling companion, and by the events on this leg of their journey. With this increase, the player begins to swing further in a spiritual or temporal direction, until one takes total precedence, and they emerge at the end of their journey.