The yellow keycard often seems like the most important one, the one you find at the end before opening a large room filled with demons.

One of the most recognizable cheat codes in gaming - typing in IDKFA in Doom 1/2 would give you all keys, all weapons, and full ammunition. What happens next is universal for every player - a chaotic vortex of bullets, shells, rockets, and plasma rounds blasting all demons into oblivion - and they can't even hide behind locked doors.

.: Coating produces great color reproduction
.: 2" square porcelain with a magnet mounted to the backside
.: Glossy finish

Doom is a video game series and media franchise created by John Carmack, John Romero, Adrian Carmack, Kevin Cloud, and Tom Hall - ID Software at the time - and all rights belong to them. If you haven't already, you should play it - it's hellishly good!

Read more about it here.

Immerse yourself in Doom with a vid below ↓