The rules for Dungeons & Dragons' playable monster races will soon be overhauled, as D&D publisher Wizards of the Coast is updating them in an upcoming book: Mordenkainen Presents: Multiverse of Monsters. There are already several different rulebooks outlining playable monsters, and a complete curated and revised collection of those is finally on the way.
The Player's Handbook for D&D offers rules for several playable races, including humans, dwarves, and elves. There were some rulebooks released after the Player's Handbook that included playable versions of the monster races. The book Volo's Guide to Monsters features a lot of these, with some monsters featuring stat penalties. These playable race rules were overhauled in Tasha's Cauldron of Everything in order to level the playing field across the board.
True to Screen Rant's earlier prediction that a new playable monster D&D book was in development, Wizards of the Coast revealed Mordenkainen Presents: Multiverse of Monsters during the "Future of D&D" panel at the conclusion of D&D Celebration 2021. It will initially be included as part of the D&D Rules Expansion Gift Set, which also includes Tasha's Cauldron of Everything, Xanathar's Guide to Everything, and a DM screen. The D&D Rules Expansion Gift Set will be released on January 25, 2022, while Mordenkainen Presents: Multiverse of Monsters will receive a standalone release in 2022.
Mordenkainen Presents: Multiverse of Monsters contains over 30 updated playable races and over 250 monsters. The book collects information from sources like Volo's Guide to Monsters, The Tortle Package, and Mordenkainen's Tome of Foes. The rules for D&D's playable races have been overhauled, with many of them receiving new abilities. The lore for each race has also been changed so that they can easily fit into campaign settings other than the Forgotten Realms. Mordenkainen Presents: Multiverse of Monsters will also feature revised stat blocks, which streamline the information presented to DMs by altering how spells are presented and more.
Wizards of the Coast also revealed that updated versions of the fifth edition core rulebooks are coming in 2024, as part of the 50th anniversary of D&D. Already being popularly referred to as "5.5," as a reference to when D&D 3E's mid-cycle rules were upgraded to 3.5E. The changes presented in Mordenkainen Presents: Multiverse of Monsters will likely set the tone for further changes to come. The playable race rules for monsters have already been altered in Tasha's Cauldron of Everything, so it wouldn't be surprising to see something similar happen with the standard playable races in the next iteration of the Player's Handbook for D&D.
The D&D Rules Expansion Gift Set will be released on January 25, 2022. Mordenkainen Presents: Monsters of the Multiverse will receive a standalone release in 2022.