Dungeons & Dragons will be a bit different when gameplay finally returns to game stores and other organized play venues, thanks to a change in Adventurer's League rules. Earlier this week, the Adventurer's League administrative team announced that players would no longer be constrained to the "PHB+1" rule that dictated character creation in previous years. This rule stated that characters could only build characters using races and subclasses found in the Player's Handbook plus one other source of the player's choosing.
This rule was originally intended to maintain character balance, as playtesting of new options was typically conducted assuming that players only owned a Player's Handbook. However, this had the effect of severely hampering players when it came to what sort of characters they wanted to build when making a character for Adventurer's League play. Although this rule change won't affect D&D players who spend their time in home campaigns, it is a big change for the thousands of players who play at stores or in conventions.
Instead, the Adventurer's League will instead base what sourcebooks players can choose from based on what kind of campaign they are playing in. All major rulebooks (which includes the Player's Handbook and expansions like Xanathar's Guide to Everything, Volo's Guide to Monsters, and Tasha's Cauldron of Everything) will be legal in all campaigns. Players in campaigns set in the Forgotten Realms can use options from Sword Coast Adventurer's Guide, while players in Seasonal Campaigns can also use options from the associated hardcover book. A full list of what sourcebooks players can use can be found here.
The Adventurer's League is the official ongoing organized play campaign for Dungeons & Dragons, providing players with the opportunity to play D&D in a continuous campaign across multiple locations. Campaigns are organized by chapters, and players can participate in these chapters at any location, provided that their character meets the chapter requirements. Most D&D games played at conventions or game stores are Adventurer's League adventurers, and Dungeons & Dragons also runs monthly online games that use Adventurer's League rules.
Dungeons & Dragons is coming off of its biggest year ever, and is at the center of a ambitious plan by publisher Wizards of the Coast to double its revenue over a five year stretch. Wizards has already announced two new products for 2021 - the Candlekeep Mysteries mystery anthology and the Van Richten's Guide to Ravenloft sourcebook.