Larn is a roguelike computer game authored by Noah Morgan in 1986 for the UNIX operating system. Morgan's original version of Larn remains part of the NetBSD games collection.
Larn is one of the shorter roguelike games. It can take many hours and tens or even hundreds of thousands of game turns to win a game of NetHack or ADOM, but Larn can reasonably be completed in one play session.
Larn is one of the first roguelike games to feature a persistent home level—in this case, a town. In addition to the player's residence, the town offers a bank, a shop, a trading post, a school, a tax administration office, and entrances to two dungeons, one of which is called a volcano.
The goal of Larn is for the player to traverse a dungeon in search of a potion that will cure his ailing daughter of 'dianthroritis'. This quest is time-limited, measured in 'mobuls'. Apart from the main dungeon's ten levels, three additional levels are located beneath a volcanic shaft. To obtain the sought-after potion, the player must first acquire adequate experience, power, and gold. Larn increases in difficulty each time finished, making it harder for players to perform in-game actions, such as destroying walls or statues. Larn also requires the player pay a tax in subsequent games based on the amount of money in the player's possession when the game was last won.
Source: Wikipedia, "Larn (computer game)," available under the CC-BY-SA License.