from the Introduction:
Across the Wide Dark Jungle is a collection of tools for running adventures in jungle settings. It’s a sequel to the original Fire in the Jungle Supplement, but doesn’t require it and differs in two ways.
First, the jungle is more fantastical or alien in nature, having a higher and thicker canopy than what is found in any jungle on Earth. This gives the jungle Floor and sub-canopy a different character than the usual “green hell” jungle environment.
Second, the default campaign type is that of an encroaching empire sending its hardiest into the jungle to acquire natural resources and valuables, with exploration, native relations, and a little treasure-seeking being necessary byproducts of the endeavor. Nonetheless, the parts and tools in this supplement can be adapted to any jungle or fantasy roleplaying campaign.