The Konami Code (known as the Konami Command in Japan) is a famous recurring cheat code in various Konami developed video games. It was identified by pressing "Up, Up, Down, Down, Left, Right, Left, Right, B, and A" (or in the case of PlayStation games, "Up, Up, Down, Down, Left, Right, Left, Right, O, and X"). Because the Metal Gear series has been published by Konami, they have also incorporated the Konami Code at various points, or at the very least referenced it.
The Konami Code was created by Kazuhisa Hashimoto while porting the arcade game Gradius over to the Nintendo Entertainment System. During testing, Hashimoto found the game to be too difficult to complete, so he put in the code which gave the player a full set of power-ups. The code was popularized in the NES version of Contra.
Usage in the Metal Gear series
In Metal Gear Solid 2: Sons of Liberty, the player can input the Konami Code shortly after clearing the game, when the clear code is on display, after which Snake will be heard either saying "What do you think you're doing!?" or "STOP FOOLIN' AROUND KID!" as confirmation of the code, although it can only be used once. The expansion pack, Metal Gear Solid 2: Substance, features a similar use to the one above, as well as an additional use where, if the player registers their save file name in Missions mode as "UUDDLRLRBA," the player will unlock all missions and characters. In-universe, the Konami Code was physically represented with Solid Snake and Otacon's handshake.
In Metal Gear Solid 3: Snake Eater, inputting the Konami Code will allow the player to see The End on the map during the boss fight with him. Also, if the player interrogates EVA in Zaozyorje, she will at one point mention the first eight inputs of the Konami Code. Inputting the Konami Code upon starting the game will likewise result in the opening credits being changed to the opening title credits, which features the people who created the opening. After clearing the game, inputting the code on the game cleared screen will have Snake remark "One More to Go..."
One of the cards for the board game Risk: Metal Gear Solid was a reference to the Konami Code.
The Konami Code was also used as the final password for the Metal Gear Rising: Revengeance teaser site, where typing it in (without commas) will unlock a sneak-peek video of the title screen for the Metal Gear Rising demo before E3. The game itself will also include the Konami Code as a means to unlock Very Hard Mode/Revengeance Mode early. Inputting it on the title screen also will have Raiden say the title of the game, mirroring a standard utilized with the Capcom survival horror franchise Resident Evil.
A limited edition button depicting the Konami Code was given out to Comic Con attendees who managed to upload Konami-related images to the Comic Con site via Instagram. The Metal Gear Solid Facebook page also added a picture of the Konami Code button and encouraged the Facebook users to either tweet the image or put it on Instagram. During the events of Comic Con, several Metal Gear fans who got the button, cosplaying as either various Militaires Sans Frontières soldiers or as Olga Gurlukovich, were also jokingly stated to have received "thirty extra lives" on the Metal Gear Solid Facebook page for gaining the badge.
Konami's annual pre-E3 shows since their inception in 2011 featured in the beginning of their video flashed the Konami Code before starting the video.
Due to the popularity of the Konami Code, it has been referenced in non-Konami developed games and pop culture (e.g. the movie Wreck-it Ralph). It has even been used in some non-Konami developed games.