Siege of Avalon was originally sold in six downloadable "chapters." Each chapter featured new maps, characters, quests, and an expansion of the general storyline. The first chapter was a free download, but the other five chapters had to be purchased. In 2001, Global Star Software released Siege of Avalon on an Anthology CD which included all six chapters. The chapters on the CD were identical to the ones that could be downloaded except for some minor changes (such as movies for the beginning and end of the game and extra chests containing unique weapons and armor). The chapters are no longer officially available to download and purchase online.
It was originally planned that a sequel would be created which would be titled "Pillars of Avalon." Digital Tome intentionally left the ending of Siege of Avalon with many unanswered questions which would be answered in the sequel. Additionally in the CD version of the Siege of Avalon, the closing movie includes a book titled "Siege of Avalon" which is placed on a shelf next to a similar book titled "Pillars of Avalon."
Because of problems with their publishers, Digital Tome eventually disbanded and shut down the Siege of Avalon website. Pillars of Avalon would therefore never be created. However, a group was given permission to modify the first chapter of Siege of Avalon to run other platforms and to distribute it as open source. Currently, nothing has been released and the source code of the game is only available on Source Forge in the project's CVS repository (search for 'soaos' on Source Forge). While there are very few CVS check-ins, the project administrator ( Dominique Louis ) assures that progress is still being made, "but Real Life keeps getting in the way of this project."
Siege of Avalon takes place in the fictional land of Eurale. Within Eurale are seven kingdoms: Nisos, Aratoy, Oriam, Fornax, Elythria, Cathea, and Taberland. The seven kingdoms united into an uneasy alliance and built a citadel as a meeting place, which was named Avalon.
Within the land is a race of nomads known as the Sha'ahoul. Their religion values very highly the earth and nature and therefore they are against farming, the building of permanent structures, and similar practices which they feel destroys the earth. After discovering the existence of Eurale, they declared war on the seven kingdoms to eradicate their way of life.
Many refugees of the destruction caused by the Sha'ahoul took shelter in Avalon. The seven kingdoms sent military support to defend Avalon and the refugees. To the people of Eurale, Avalon is seen as the last hope at stopping the Sha'ahoul. The Sha'ahoul and their leader, Mithras, chose to overtake the citadel by setting up a siege around it.
The game begins with an entry in the hero's journal. The siege has been going on for several years. His brother, Corvus, serves as part of the military in Avalon. When their father dies, the hero feels that it is his obligation to inform Corvus of the sad news, so he becomes part of the crew of a ship sailing from Elythria to Avalon to deliver supplies. The Sha'ahoul manage to sink all of the ships except the one the hero is on. The ship reaches Avalon, but has lost most of its supplies. It is not possible to make a return voyage to Elythria and so the hero decides to stay at Avalon, inform Corvus of their father's death, and help out Avalon in whatever manner he can. The player gains control at this point and begins by speaking to Corvus and informing him about his father's death. His brother then goes out into a raid party against the Sha'ahoul but is betrayed and Corvus is the only one left in the party. So the hero goes into the ruined village to find and save his brother eventually helping the people of Avalon with many quests and tasks and becoming a knight of Avalon.