Legends of Cosrin, often called Cosrin, is a fantasy multi-user dungeon created and maintained by Online Games Company. The game was released in 1999 on AOL Europe after the success of its parent MUD, Legends of Terris.

As with all multi-user dungeons, Cosrin is a text-only game. However, Cosrin is different in that instead of using a popular telnet client such as zMUD or GMUD to connect to the game, connections are restricted to those using the game software provided by Online Games Company (OGC), commonly called a 'game wizard'.

Work on the game wizard began in the year 2000, a year after Cosrin's release. It is similar to telnet clients in that it provides functions such as highlight strings, macros, and aliases for users to use in exploring the text-only world, however, it is also different from telnet clients in that it provides a useful and colorful interface specifically tailored for play in 'Legends of Cosrin'.