I need a world that is hard, but not impossible, to live on but also to be found on. How can I best accomplish this?
I am working on a world sort of like the planet in the movie Predators. In the world I'm working on, a race uses it for military special-ops training. They take a death-row prisoner and drop them on this world with minimal gear/supplies and leave them there. Trainees are then tasked with hunting them down.
I want this world to be as difficult to live on, traverse, or track someone down on as possible without downright killing them immediately.
I want interesting or unconventional ideas, not just "A jungle world". I want ideas that will make a jungle look easy to traverse. Aspects about this world that, at first, seem irrelevant but render entire strategies useless. Details that turn this planet (or moon) into a living hell.