Deadly Towers is an action role-playing video game developed by Lenar and exclusively-licensed by Irem as a software title for the Nintendo Entertainment System (NES). It was released in Japan on December 15, 1986, and in North America in September of the following year. One of the earliest published role-playing video games for the NES in North America, Deadly Towers was a best-selling title in 1987. In Japan, Deadly Towers was titled Mashō (魔鐘), literally meaning "Evil Bell". It is a pun of the word mashō (魔性), meaning "devilishness", and in keeping with this theme, the Japanese cartridge contained a red LED at the top which illuminated when turned on. Irem intended the game's English-language title to be Hell's Bells, but Nintendo of America refused to issue the game a Nintendo Seal of Quality unless Brøderbund changed the name.