From the publishers blurb: We need your help! The marshes are burning, and we don't know why! The Bone Marshes is a tabletop adventure about getting lost. It’s tailor-made for groups that enjoy exploring complex spaces and drawing maps. The book contains (in brief): Hexcrawl in a burning, shifting marsh Underground chambers and tunnels that flood with the tides Lost Alien Technology Four mini-dungeons Old-school rules based on Knave, compatible with any d20 system 100+ random items