The Uncharted Swamp (2019)

From the publishers blurb:
One of the hallmarks of old-school-style role-playing games is a preference for player-driven rather than referee-dominated plots. The reasons for this opposition are that role-playing requires active player participants and an honest game cannot have a foregone conclusion. But creating a true sandbox in which the players characters are free to explore in any direction, their actions seemingly limited only by those actions’ consequences, can be really dang hard.

For instance, let’s say there’s a path that leads from a village to a dungeon. Or several paths. Each path is dark, twisty, and overgrown— and has its own set of preplanned challenges. The players have chosen to travel from the village to the dungeon. But they don’t want to use any of the paths. They don’t even want to creep along in the undergrowth while staying near the
path. They want to traipse through miles of uncharted wilderness and approach the dungeon from the opposite side.

Good for them—they outsmarted the enemy. But they’ve also outsmarted you. (If you’re
thinking, “my players love it when I just wing it!” stop reading now, this product is not for you.)

This adventure aims to solve the problem of dealing with random overland movement through a swamp by offering the referee a really really good random encounter table that doesn’t feel random, but instead hangs together in a meaningful way. In addition to true "wanderers," it also describes a few lairs whose location is not pre-determined, but fixed in the course of play.

This adventure is "pay what you want" because it's an unproven concept delivered by an untested designer. Go ahead, take a look. If you love it as much as I hope you will, you can pay me later or, better yet, tell your friends.

Best for levels 1 - 5.