Players : we open the door Me : ok. How exactly are you proceeding ? Do you touch the handle ? Them fretting for a minute, doing a couple checks, and finally trying the handle Me : the door opens no problems Them : what happens ? Me : nothing special.

Dont worry, I just do it once or twice per dungeon. It helps them remember to check the trapped doors.

It’s a difficult one to rule, as suddenly being meticulous about positioning and line of sight telegraphs that the players should suddenly be focused on these things. I usually just have them roll luck or try to perceive the threat before they accidentally trigger its ability. If they fail, they get a Medusa blast

Your horrible what?

Want to really mess with your players, make a note of who looked and then occasionally ask how many long rests they have taken since they looked.

You may need to split the cardiologist visit bills with them though.