Adventure game
An adventure game is a video game in which the player assumes the role of a protagonist in an interactive story driven by exploration and puzzle-solving. The genre's focus on story allows it to draw heavily from other narrative-based media, literature and film, encompassing a wide variety of literary genres. Many adventure games (text and graphic) are designed for a single player, since this emphasis on story and character makes multi-player design difficult. "Colossal Cave Adventure" is identified as the first such adventure game, first released in 1976, while other notable adventure game series include "Zork", "King's Quest", "The Secret of Monkey Island", and "Myst".
Tabletop role-playing game
One of the first original role-playing games was M. A. R. Barker's "Empire of the Petal Throne", first published in 1974, the same year as "Dungeons & Dragons". It introduced the fictional world of Tékumel, influenced by Indian, Middle-Eastern, Egyptian and Meso-American mythology. It also introduced the game mechanic of critical hits. Using these rules a player who rolls a 20 on a 20 sided die does double the normal damage, and a 20 followed by a 19 or 20 counts as a killing blow. According to creator Barker, "this simulates the 'lucky hit' on a vital organ." The game influenced Arneson and Gygax, who was so impressed with it that his company TSR published "Empire of the Petal Throne" in 1975. TSR published Barker's game and setting as a standalone game, rather than as a "supplement" to the original "D&D" rules.