|This article is written from the Real Life point of view|
ENGAGE RIDLEY MOTHER FUCKER is an infamous password within Metroid. Because it references an invalid starting location and generates a ridiculous game time value of 2,861,643,271, equivalent to 314.5 years, this password has different (albeit undesirable) effects depending on whether a console or emulator is used. Entering the password will either cause the game to be directed back to the title screen like the
333333 KKKKKK password. Entering it can also cause the game to crash at a black screen; this is most common on the Nintendo 3DS Virtual Console version. Amusingly, the game state this code generates does result in Ridley having been defeated.
Entering the code on the original 5-pin cartridge will crash the console, forcing the player to restart the NES entirely.
Entering the code on the 3-pin cartridge version of the game will cause a screen-wide graphical glitch that prevents the screen from scrolling to the left or right, trapping a suitless Samus on the first screen of Brinstar. 
Game Boy Advance
Wii and Wii U
Entering the code into the 3DS version Hard-Bricks the system, forcing the user to hold down the Power Button to enter Emergency Reset, or in some cases, replace their entire system.
NES Classic Edition
Entering the code into the NES Classic version causes this error, subsequently crashing the game:
C7: An error has occurred. If the problem persists, please make a note of the error code and visit support.nintendo.com.
This error can occasionally Soft-Brick the system, requiring the Power button to be held down.
If the error persists, the system is considered 'defective' and has to be replaced.
Nintendo Switch Online
Entering the code into the Nintendo Switch Online version causes this error, subsequently crashing the game:
An error has occurred within the game.
There is a playable version of the Engage Ridley password (see above). It starts Samus in Tourian suitless, with the Varia Suit, 82 Missiles, 3 Energy Tanks, the Ice Beam and no Morph Ball. Because the Morph Ball is needed to backtrack, there is no choice but to fight Mother Brain, unless a second controller glitch is used to warp Samus back to Brinstar.
- ^ DA Boredman (2009-01-26). The Best Metroid Password. Retrieved on 2014-04-22.
- ^ McWhertor, Michael (2011-08-31). Under No Circumstances Should You Use This Dirty Password on Metroid for Nintendo 3DS. Kotaku. Retrieved on 2013-03-16.
- ^ Flathead Sam (2016-12-04). Engage Ridley on the Mini NES. Retrieved on 2016-12-29.