, , , , , , ,

When travelling the depths of the underdark, there are passages and caves that most “civilized” denizens ignore because they are small, narrow, and fraught with obstacles. These “tertiary” passages sometimes make for useful escape or access tunnels and these have their connections to the primary and secondary passages concealed behind secret doors or other hidden access points.

Tertiary Passages into the Depths of the Earth

Tertiary Passages into the Depths of the Earth

Tertiary tunnels are usually about ten feet wide with ceilings between 8 to 25 feet with an average of 15 feet or so. While drow still patrol these passages, encounters are more frequently with monsters such as xorn, lurkers above, trappers, mind flayers, and various underdark vermin.

This set of tertiary passage geomorphs includes a redraw of the original from Descent into the Depths of the Earth (on the far left), along with four new example passages for use when handling encounters along these nearly abandoned and secret byways.


The maps on Dyson’s Dodecahedron are released for free personal use thanks to the support of awesome patrons like you over on Patreon. Every month 400 patrons come together to make these releases possible. You can help too in order to keep the flow of maps coming and to improve their quality – and even get a map of your own!