An ancient prophecy states that King Fudd the Bewildered will die peacefully, his daughter accompanying him during his last hour. However, Princess Lorealle the Worthy mysteriously disappears, abducted by her stepmother Morgana, who intends to put her own daughter on the throne. In order to prevent the princess from being rescued by a valiant knight, Morgana makes sure that the Union Hall selects the most unworthy one for this valiant task: Eric the Unready, known for bringing the book "How to Joust" to his duels.

Eric the Unready is a humorous text adventure with graphics, similar in concept to Legend's own Spellcasting series. Like in those games, the player can select combinations of verbs and objects from a list to interact with the environment, but is encouraged and sometimes required to type commands as well. Some scenes display full-screen character portraits with pre-set dialogue choices. The game often makes verbose humorous comments on the player's actions, including many completely optional and arbitrary ones. It contains many segments that parody various aspects of contemporary pop culture as well as other video games.