The D&D Adventurers League is an ongoing official campaign for Dungeons & Dragons (5th Edition). It uses the fifth edition Dungeons & Dragons rules, and features the Forgotten Realms setting. You can play D&D Adventurers League games literally anywhere. Players use the fifth edition rules to create a character and bring that character to games anywhere D&D Adventurers League play is happening.
This family links together the seasonal storylines of Adventurers League play; it does not include all the items in these series.
The Adventurers League contains several distinct types of scenarios:
DDEX/DDAL (D&D Expeditions / D&D Adventurers League) Adventures - These are short, two-to-eight hour adventures that are associated with a given season’s main storyline. They are typically set in a single location based on the season and span multiple tiers.
DDEP (D&D Epic) Adventures - These are epic adventures that require two or more tables to play simultaneously, and generally have an element in them that allows the tables some degree of interaction with one another. They frequently have higher-than-average rewards but can be much more difficult than the DDEX/DDAL adventures.
DDAO (D&D Author Only) Adventures - These are adventures that only the author can run; the authors are all D&D Adventures League administrators or other employees of Wizards of the Coast.
CCC (Convention-Created Content) - These adventures are produced by independent organizations for use at local conventions. While they are initially exclusive to the convention that commissioned their production, they are required to be made available for general purchase within six months of their initial release. CCC adventures do not count towards any DM Quests involving DD-series adventures.
DDIA (D&D Introductory) Adventures - These introductory adventures support the release of hardcover Wizards of the Coast product releases. If the product in question is an adventure, then the introductory adventure is typically a short adaptation of a single chapter from that product. Otherwise, the introductory adventure is an original adventure that utilizes new content from a non-story product.
Hardcover Adventures. These adventures are officially produced and published by Wizards of the Coast. Not all of them have actual hardcovers (see e.g.Cloud Giant's Bargain).
Other Content. Sometimes weird things happen (e.g. PAX West) and additional content is made available for Adventurers League Play. As a general rule, if it is produced by Wizards of the Coast or the Adventurers League staff and bears the Adventurers League logo, it counts.
Adventurers League scenarios generally are divided into seven play seasons, each season anchored by a commercial hardcover:
Note that a tremendous amount of third-party materials have been produced for each play season; often these are marketed with similar titles, covers, and so forth, in an effort to conflate them with the official play season products and titles - caveat ludio.
Note - in the "Linked Items" box under the "Relationship:" drop-down, select "RPG Series" to review the storyline series associated with this family.