ah, too bad that article only has basically one example, and everything else accessible via a few Google searches is complete trash on the subject :(

it seems the standard seems to be somewhere around "ordinary care" and reasonably expecting trespassers

so - to my layman eyes - it seems simple, that if someone slips while crossing my field/forest and it's in its natural state, then I contributed nothing :)

built environment is different (and usually well demarcated), and the problem is probably with backyards and front lawns and other gardens, where people leave out stuff, let's say a saw.