Set in the pseudo-medieval kingdom of Ehb, the high fantasy game follows a young farmer and her companions as they journey to defeat an invading force.

Unlike other role-playing video games of the time, the world of Dungeon Siege does not have levels but is a single, continuous area without loading screens that the player journeys through, fighting hordes of enemies.

Dungeon Siege sold over 1.7 million copies, and was nominated for the Computer Role-Playing Game of the Year award by the Academy of Interactive Arts & Sciences.

[1] The player chooses the gender and customizes the appearance of the main character of the story prior to the start of the game and typically controls them.

[2] Characters can equip weapons, armor, rings, and amulets, which provide attack or defense points, or give bonuses to some other statistic.

Multiplayer matches can be created and joined via local area networks, direct IP addresses, and, prior to its closure in 2006, through the Microsoft Zone matchmaking service.

[7] Dungeon Siege is set in the Kingdom of Ehb, a varied region on the continent of Aranna containing deserts, swamps, forests, and mountains, created three centuries earlier at the dissolution of the Empire of Stars.

[12] The player fights through monsters and bandits in crystal caves, a forest, a swamp, and an underground Goblin fortress filled with mechanical war machines.

After recovering the Staff from the Goblins, the player character meets a division of the 10th Legion and is pointed towards Fortress Kroth, which has been overrun with undead.

[18] Dungeon Siege was inspired by prior role-playing games such as Baldur's Gate and the Ultima series, but primarily by Diablo, which Taylor admired for having an experience that "concentrated on action" that players could jump into without first researching the gameplay details and settings.

[17] Taylor wanted to expand that concept into a streamlined, immersive, and action-heavy role-playing game that removed common elements of the genre that he found boring, frustrating, or slow.

[21][22] The plot of the game was intended by Taylor to be subordinate to the gameplay; to that end, he was unconcerned that his overall story arc was considered, even by the development team, to be somewhat of a cliché, as he felt that journeying to defeat an "ultimate evil" was very motivating to players.

[17] The development team also tried to make the game more streamlined by removing the need to backtrack to previously visited towns to sell items, by adding inventories to companion characters and pack mules.

[26][27] According to Kijanka, the developers also spent a lot of time changing technologies mid-development, such as building a custom animation editor before moving to a licensed one, and starting with the OpenGL graphics library only to switch to Direct3D.

[18] As a result, the team was required to work 12- to 14-hour days and weekends for most of the development time in order to complete the game within four years.

[42] By September 2002, Dungeon Siege had also received a "Gold" certification from the Verband der Unterhaltungssoftware Deutschland (VUD),[43] indicating sales of at least 100,000 units across Germany, Austria and Switzerland.

[2][4][33][35] Suciu further praised how the freeform, seamless map was used to create areas that were not shaped like rectangular regions with a winding path filling up the space, as was typical with other role-playing games of the time.

[2][3][35] Adams further added that many of the tactical choices in the game were inconsequential, as all battles quickly devolved into brawls, and that the freeform system of leveling was essentially the same as four character classes as pursuing multiple tracks was ineffective.

[1][33][34] Overall, Vederman of PC Gamer called Dungeon Siege "one of the best, most enjoyable games of the year" and GamePro's reviewer claimed it "walks all over its competition with almost effortless grace", while Adams of IGN concluded that it was entertaining but had "untapped potential".

[17][51][52][53] Gas Powered Games released one mod of their own in July 2002 titled "Yesterhaven", created by six designers over six weeks, which provided a short multiplayer storyline for low-level characters wherein they defended a town from three thematic plagues of monsters.

[54][55] It was followed up by Legends of Aranna, a full expansion pack developed by Mad Doc Software and released on November 11, 2003 for Windows and Mac OS X by Microsoft.

[56] The expansion pack added little new gameplay besides new terrains, creatures, and items, but featured an entirely separate story from the original game.

[57] In Legends, the player controls another unnamed farmer; after the Staff of Stars is stolen by a creature called the Shadowjumper, they set off to retrieve it.

After fighting their way through monsters in icy hills, jungles, and islands, the player arrives at the mystical Great Clock, a giant artifact which controls Aranna's seasons.

[57][59][60][61] At the 7th Annual Interactive Achievement Awards, the AIAS nominated Legends of Aranna for "Computer Role-Playing Game of the Year", though it lost to Star Wars: Knights of the Old Republic.