The gameplay of Myst consists of a first-person journey through an interactive world. The player moves the character by clicking on locations shown on the screen; the scene then crossfades into another frame, and the player can continue to explore. Players can interact with specific objects on some screens by clicking or dragging them. To assist in rapidly crossing areas already explored, Myst has an optional "Zip" feature. When a lightning bolt cursor appears, players can click and skip several frames to another location. While this provides a rapid method of travel, it can also cause players to miss important items and clues. Some items can be carried by the player and read, including journal pages which provide backstory. Players can only carry a single page at a time, and pages return to their original locations when dropped.
To complete the game, the player must explore the seemingly deserted island of Myst. There the player discovers and follows clues to be transported via "linking books" to several "Ages", each of which is a self-contained mini-world. Each of the Ages—named Selenitic, Stoneship, Mechanical, and Channelwood—requires the user to solve a series of logical, interrelated puzzles to complete its exploration. Objects and information discovered in one Age may be required to solve puzzles in another Age, or to complete the game's primary puzzle on Myst. For example, in order to activate a switch, players must first open a safe, after discovering its combination, and then use the matches found within to start a boiler.
Apart from its predominantly nonverbal storytelling, Myst's gameplay is unusual among adventuring computer games in several ways. The player is provided with very little backstory at the beginning of the game, and no obvious goals or objectives are laid out. This means that players must simply begin to explore. There are no obvious enemies, no physical violence, and no threat of "dying" at any point, although it is possible to reach a few "losing" endings. There is no time limit to complete the game. The game unfolds at its own pace and is solved through a combination of patience, observation, and logical thinking.
Players assume the role of an unnamed person known as the Stranger, who stumbles across an unusual book titled "Myst". The Stranger reads the book and discovers a detailed description of an island world called Myst. Placing his hand on the last page, the Stranger is whisked away to the world described and is left with no choice but to explore the island. Myst contains a library where two additional books can be found, colored red and blue. These books are traps that hold Sirrus and Achenar, the sons of Atrus, who once lived on Myst island with his wife Catherine. Atrus writes special "linking books" that transport people to the worlds, or "Ages", that the books describe. From the panels of their books, Sirrus and Achenar tell the Stranger that Atrus is dead; each brother blames the other for the death of their father, as well as the destruction of much of Atrus' library. Both plead for the Stranger to help them escape. However, the books are missing several pages, rendering the sons' messages initially unclear and riddled with static.
As the Stranger continues to explore the island, books linking to more Ages are discovered hidden behind complex mechanisms and puzzles. The Stranger must visit each Age, find the red and blue pages hidden there, and return to Myst Island. These pages can then be placed in the corresponding books. As the Stranger adds more pages to these books, the brothers can be seen and heard more clearly. After collecting four pages, the brothers can talk clearly enough to tell the Stranger where the fifth and final missing page for their book is hidden; if the Stranger can complete either book, that brother will be set free. The clearer dialog also allows the player to more accurately judge each brother's personality. The Stranger is left with a choice to help Sirrus, Achenar, or neither.
Sirrus and Achenar beg the Stranger not to touch the green book that is stored in the same location as their final pages. They claim that it is a book like their own that will trap the Stranger. In truth, it leads to D'ni, where Atrus is imprisoned. When the book is opened, Atrus asks the Stranger to bring him a final page that is hidden on Myst Island; without it, he cannot bring his sons to justice. The game has several endings, depending on the player's actions. Giving either Sirrus or Achenar the final page of their book causes the Stranger to switch places with the son, leaving the player trapped inside the Prison book. Linking to D'ni without the page Atrus asks for leaves the Stranger and Atrus trapped on D'ni. Linking to D'ni with the page allows Atrus to complete his Myst book and return to the island. Upon returning to the library, the player finds the red and blue books gone, and burn marks on the shelves where they used to be.