Castlevania, known as Akumajō Dracula (悪魔城ドラキュラ, Akumajō Dorakyura, officially translated Devil's Castle Dracula) in Japan, is a console video game developed and published by Konami for the Family Computer Disk System in Japan in September 1986. A year later, in May 1987 it was ported to cartridge format and released in North America for the Nintendo Entertainment System (NES) followed by a European release in 1988. It was re-released for the Family Computer (FC) in cartridge format in Japan in 1993. It is the first game in Konami's Castlevania video game series. It was considered a hallmark of videogame potential in the NES era.

The player takes control of Simon Belmont in the year 1691, who must defeat the vampire Dracula. A sequel, Simon's Quest, was released for the NES in 1988.

Castlevania is a typical platform game of the 8-bit era: the game is composed of six levels, which are played in a strictly linear progression. The player controls Simon Belmont throughout the game. The A button allows Simon Belmont to jump just like other platformer games, such as Super Mario Bros., but he can only jump straight up, left, or right; there is no midair control. There are many stairs located throughout the levels, but rather than simply pressing left or right to step up them, the player must initially press up on the directional pad. His primary mode of attack is via his whip by pressing the B button, which can be upgraded twice by obtaining special items throughout the course of the game which change it into a chain whip and extend its length. In addition, various "sub-weapons" can be obtained which provide different means of attack. By breaking candelabra and certain other items located throughout the castle, Simon collects "'hearts," which are then used as ammunition for the sub-weapon that he possesses. Simon can only carry one sub-weapon at a time. The player can use a sub-weapon by simultaneously pressing "up" and B on the controller. Whenever Simon receives damage, he is knocked back a distance, increasing the challenge as this may lead to him falling down into a pit below. He is not knocked back when on stairs.

Each of Castlevania's six levels conclude with a boss fight: these bosses are generally taken from horror literature or legend, and include a giant bat, Medusa, a pair of mummies, Frankenstein's Monster and Igor, the Grim Reaper, and finally Dracula (who transforms into a second and more powerful monster form after his first form is defeated).