The Konami Code: Up Up Down Down Left Right

Up, up, down, down, left, right, left, right, B, A. Ten button presses, learned by millions of children who never owned the game it was written for. The sequence is called the Konami Code, and it was never supposed to leave the office.

In 1985 Konami released Gradius, a side-scrolling shooter, in Japanese arcades. A year later the company ported it to the Nintendo Entertainment System, and the porting work fell to a developer named Kazuhisa Hashimoto. Hashimoto found the home version brutal — he could not survive long enough to test the later levels. So he wrote a cheat: pause the game, enter the sequence on the controller, and you got the full kit of Gradius power-ups all at once, the same upgrades the game normally doled out across an entire playthrough.

The code was a debug tool meant to be stripped before shipping. It was not stripped. The team noticed only as the cartridge was being prepared for mass production, and pulling it risked introducing fresh bugs into a game already at the printer. They left it in. Hashimoto picked the sequence because it was easy for testers to remember and almost impossible for a player to enter by accident during gameplay.

Konami reused it. It appeared in the company's later releases, but it became globally famous through the 1988 NES port of Contra, where the same ten buttons granted the player thirty lives instead of three. North American children traded the sequence on playgrounds. It picked up the names "Contra Code" and "30 Lives Code." Konami built it into sequels and spin-offs across multiple franchises.

Then it escaped Konami entirely. Wreck-It Ralph in 2012 has the villain King Candy use the code to access locked game code in Sugar Rush. Bloodstained: Ritual of the Night unlocks a "1986 Mode" with it, the year of the original Gradius. BioShock Infinite uses a variant to unlock 1999 Mode. Fortnite hid it in the Chapter 1 Season X black hole event in October 2019, accessible for thirty-eight hours. The Bank of Canada's commemorative ten-dollar banknote site plays a chiptune version of O Canada when you enter it. Recite it to Siri and she calls you a cheater. Recite it to Alexa and she activates "Super Alexa Mode," announcing reactors online. A Fisher-Price toddler controller plays a special light-and-sound sequence on entry. The Moldy Peaches sang it in 2001: "Up up down down left right left right B A start."