From publisher blurb:
Highfane Peaks is a setting toolkit designed to help you build evocative adventures in a mythological mountain range.
A 70+ page setting guide for Five Torches Deep
Detailed mountaineering rules
New lineages, classes, spells, monsters, and equipment
Guidelines on adventuring in an arcanely-drenched mountain range
High concept: what if dungeons were on mountain peaks instead of underground?
Five Torches Deep: Highfane Peaks is a compact compendium of rugged climbs and ancient magic. Here's a quick summary of its key elements:
Old-school plus 5e. Highfane Peaks is built for Five Torches Deep, the best selling OSR minded 5e hack. As such it works with just about any fantasy adventure game that uses a d20. While there are a few widgets that specifically cater to FTD, the majority of the book is a collection of tools and tables to help create adventures in a sorcerous mountain range.
A setting of aberrant temples carved atop magically-birthed mountains. A long-dead progenitor people known as the Shapers created the eponymous range at the edge of the world. Some say that these peaks are where all life began; others that it is a foul place haunted by the sins of careless mages. Dig into dozens of pages of spells, monsters, loot, adventure hooks, and people in our typical concise style all designed to fit within an evocative setting.
New rules for mountain-based adventures. New lineages, classes, equipment, and subsystems to make ascents feel like a hazardous trial of mountaineering rather than a quick montage of exposition. Play as the bizarre clayfolk constructs left behind by the Shapers, tame an infamously agile rockgoat to be your loyal steed, and try to avoid being conscripted into the ghost armies of the aurorawyrms that rule the night skies.