The Verdant Realm
This is earth at the end of the dominion of humans. The last refuges of humanity are at the poles, but each year they melt farther in summer and freeze less in winter. The center latitudes have been overrun by a toxic forest, deadly to mammals. Rumors of strange insects and animate plants spread from the floating refugee camps on boats in the Arctic and Antarctic circles. Plants gained various levels of sentience about 40 years ago, and genetic mutations from UV rays began 150 years ago. Mammals are now at the bottom of the food web, commonly hunted by increasingly large birds, reptiles, amphibians, crustaceans, cepholopods, and…plants.
The mutated Survivors of the Verdant Realm are rangers, herbalists, hedge wizards, rogues, barbarians. (Other suggestions welcome.)
The Verdant Lands are divided into zones based on habitability and ease of foraging. The map is a future Earth, 60 meters farther under the ocean.
Assume the basic tech we have now, with completely unreliable weather patterns and resource access. At the beginning of any expedition away from "home base," you will need to research your destinations. You may be able to locate libraries, possibly with access to LANs, print copies of Wikipedia circa 2017, etc. Be creative with both what you think you can access and with what you think you will find.