https://en.wikipedia.org/wiki/Boss_key

Some older games, like Wolfenstein 3D, had a special shortcut that turned the game screen into a fake DOS screen or similar. It was a funny feature, and surely has saved someone from suffering a heart attack at the office.
That kind of feature became practically obsolete with multitask operating systems. Anyway, I felt somehow nostalgic for it this morning. I think modern games should include it, as a homage or something.

Has anybody here ever been in need of a Boss Key? Or even used it at a critical situation?

This is what Super+M or alt+tab is for. Those boss keys existed back when you could only run a single program.

English is not the official language at my area, so boss key never worked for me.

Well, they weren't extremely super convincing anyway. You had to be pretty lucky for the non-interactive boss display to match what you were supposed to do (even if some games had three or four kind of displays), or you boss had to be pretty clueless about what he asked you.

It was mostly a joke, was it ? Is there any documented case of anyone having ever fooled anyone anywhere with a boss key ?

I think so... Although I have met some bosses that could have been easily fooled by this.

I'm pretty sure most 'boss keys' were parodies that brought up something even more embarassing.

"Here comes my boss, I can't let him see me playing Pong, so I hit CTRL+B and... it now looks like I'm writing a letter to the FBI accusing him of being a serial killer with a sheep fetish. That'll help me keep my job!"

Oh I remember that in one game I used to play. You'd press a key and get a big mass of technical looking diagrams.

One of the webcomics I read, PHD Comics, has a boss key on their website.

This is what you get:

http://phdcomics.com/archive_journal.php?n=2010

Damn. Figure 1. is even an antiboss-key. "Hey, looks like you're reading a boring academic article here ?" *clickyclic* "No no just a regular webcomic, see."

When I read the title, the first thing that sprang to mind for me was http://zelda.wikia.com/wiki/Boss_Key