Metal Gear (Japanese: メタルギア, Hepburn: Metaru Gia) is a series of action-adventure stealth video games, created by Hideo Kojima and developed and published by Konami. The first game, Metal Gear, was released in 1987 for the MSX2 home computer architecture. The player takes control of a special forces operative (usually Solid Snake or his father, Big Boss) who is assigned to find the titular superweapon "Metal Gear", a bipedal walking tank with the ability to launch nuclear weapons. Several sequels have been released for multiple consoles after requests from Konami to produce new Metal Gear games. The sequels expand the original game's plot adding new characters opposing and supporting Snake, while there have also been a few prequels exploring the origins of the Metal Gear and recurring characters. Various parts were inspired by Hollywood films with character's names, settings and artworks often referencing them.

Other notable traits are cinematic cutscenes, intricate storylines, offbeat and fourth wall humor, and exploration of political and philosophical themes, with references to Hollywood films to add flavor. As of March 2015, 41.2 million copies of the game franchise have been sold worldwide, with individual installments having been critically and commercially acclaimed and having received several awards. The franchise has also been adapted into other media such as comics, novels, and drama CDs. Snake also appeared as a guest character in Super Smash Bros. Brawl.

The Gradius (グラディウス, Guradiusu, pronounced: Gra-dee-us) games, first introduced in 1985, make up a series of scrolling shooter video games published by Konami for a variety of portable, console and arcade platforms. In many games in the series, the player controls a ship known as the Vic Viper. In other games of the series, ships the player controls include the Lord British Space Destroyer, Metalion, Sabel Tiger, Thrasher, Vixen, Alpinia, Super Cobra, Jade Knight, and the Falchion β.