/r/rust, the subreddit for the Rust language, regularly (every 1-2 days at most) gets posts meant for /r/playrust, the subreddit for the Rust game. I genuinely don't know how people manage to get as far as posting without noticing where they are.
It is hard to perceive that which you are not aware exists even with obvious evidence in your face
It’s probably because the “create a Reddit post” form doesn’t require you to even visit the subreddit you are posting to. It DOES show you the rules/sidebar of the subreddit you are about to post to (for /r/rust it includes a link to /r/playrust for the gamers) but apparently many aren’t seeing that.