EverQuest: Lost Dungeons of Norrath (also known as LDoN) was the sixth expansion pack for the EverQuest MMORPG. It was made available as a digital download in September 2003. However, purchasers of the retail box version were rewarded with an in-game item (a magic bag), starting Sony's trend to include in-game items as incentive to purchase retail copies of their expansions.
Lost Dungeons of Norrath introduced broad-based instanced dungeons to Norrath, revolving around tales of the Wayfarers - an NPC adventuring organization. Players complete adventures for the Wayfarers in one of five different dungeon themes. Each dungeon theme has about ten different variations of the zone, and players can also choose the type and difficulty of their adventure. When the adventure is finished successfully, players are awarded Adventure Points which can be spent on items, spells, and 'augments' at the Wayfarer camps.
Augments were introduced in Lost Dungeons of Norrath and allow players to enhance existing items by adding an augment to them. Existing items in the game had generally only a single augment slot, so only one augment could be added. Items purchased at the Wayfarer camps occasionally had up to three slots available to augment.
In addition to group adventuring, the Wayfarer camps also offered raid content, in which multiple groups could challenge difficult high-end content.
Source: Wikipedia, "EverQuest: Lost Dungeons of Norrath", available under the CC-BY-SA License.