Izirion's Enchiridion of the West Marches

Izirion’s Enchiridion of the West Marches contains everything you need to run your own West Marches game in Fifth Edition or an OSR system, or to create a grimy, player-driven wilderness sandbox suitable for any campaign.
Here, at the end of the road, there lie uncharted wilds, where courage of heart and the spirit of discovery still ring true. Here, beyond the edge of the map, relentless peril may crush the soul of the unworthy, yet it shall stoke the embers of greatness. Here, amidst the ruin and brimstone, awaits the forge of heroes, where legends are tempered in fire and blood.
Welcome to the West Marches.
Izirion’s Enchiridion is a guide and toolbox for running your own games in the campaign style of the West Marches, designed to facilitate a large pool of players that create their own parties and plan their own missions to explore a sprawling, persistent wilderness. As they delve deeper into the Marches, they will uncover ancient mysteries, challenge mighty foes, and blaze the path that will determine their fate.
Inside, you will find rules for wilderness travel and exploration, toolkits for building your own regions and factions, and guidelines for writing and designing complex layers of history.
Izirion's Enchiridion is written with Fifth Edition in mind, but is easily compatible with most OSR systems (the book includes conversion guidelines).