What is a TPK? Why do they happen? And what can we do to prevent them from happening at our table?
Metagaming is one issue we encounter in tabletop RPGs. Players have their characters act on player knowledge that their character does not possess. A DM's defense against this is to gently remind the player to act within the confines of character knowledge.
This can lead to an overcorrection where every time a single PC finds out information, the other players ask "do you tell us that?" Any time a strange routine like this becomes habitual, we should streamline the process.