Which 3rd party D&D nested random encounter resource includes combat/social/treasure/mystery encounters for each type of environment?

Question

I had once found a nested random encounter resource, as in there was a master table to determine the whether the party discovered interesting terrain, combat, mysteries, etc and one could then find associated tables for those encounter types for various environments: arctic, trade road, forest, grassland, underwater...

This book was very similar to Necromancer Games 2003 Mother of All Encounter Tables except as I had stated previously unlike MOAET the book I am looking for includes many different types of possible discoveries to come across whereas MOAET simply lists possible monsters one might find and fight in a particular biome.

I do not remember many of the encounters from this book but one that had stuck out in my mind is one from the arctic table where the party comes across a metallic device generating heat in the snow, as if to imply alien or future technology.

Does anyone know the name of this resource or where to find it?

Answer 1

Other than the master table, this sounds like Chapter 2 of Xanathar's Guide to Everything. Here's the encounter I think you're referencing from Arctic Encounters (Levels 17-20):

d100	Encounter
21-25	A circular patch of black ice on the ground. The air temperature around the patch is warmer than in the surrounding area, and characters who inspect the ice find bits of machinery frozen within.

Here's the table of contents:

• Arctic Encounters
• Coastal Encounters
• Desert Encounters
• Forest Encounters
• Grassland Encounters
• Hill Encounters
• Mountain Encounters
• Swamp Encounters
• Underdark Encounters
• Underwater Encounters
• Urban Encounters

It's possible that the third party resource was just a copy of the encounter tables from this chapter.