depends on how you define “adversarial”

I’ve given out powerful items, that had downsides when used, but my players enjoyed figuring out stuff like that.

I’ve also ran dungeons that featured potential lethal traps, but i think thats ok if the presence of such a trap is telegraphed enough that players know they better go slow and ask questions about their environment or describe how they are checking a room. I did not plan that you could get a pressure plate stuck by pouring sand between tiles, but you described doing it and explaining your intention so it became the solution. if you’d chosen to rush through the room filled with gore or strange scratch marks on the floor or obvious vents in the ceiling, then i’d have rolled if you trigger a trap, and then you might die trying to escape poison gas or being crushed by a moving wall, if the dice keep falling that way.

i only create situations (and those are often dangerous, and have a chance of characters dieing), but at the table i am the biggest fan your characters have and can’t wait to see how they crawl out of the dungeon with treasure beyond believe.