LEGO Batman: Legacy of the Dark Knight gets Mayhem Collection DLC: arrives September 18

Warner Bros. says LEGO Batman: Legacy of the Dark Knight is getting its first major DLC on September 18: the paid Mayhem Collection. That release lands the same day the game makes its Nintendo Switch 2 debut, after the base game first arrived on PlayStation 5, Windows, and Xbox Series X/S on May 22, 2026.

Warner Bros. says the Mayhem Collection brings in a new story mission centered on Joker and Harley Quinn, with the pair breaking out of Arkham Asylum. It also adds Mayhem Mode, a timed Gotham City chase that lets you play as Joker and Harley while Batman and Robin hunt you down, plus the Sinister Pack, which includes DC Comics-inspired outfits and a Jokermobile.

If you were hoping to see more from Batman’s rogues’ gallery, this looks like the DLC to pick up, especially since Warner Bros. and TT Games still haven’t said much about any larger post-launch roadmap. The base game already pulled in generally favorable reviews, with praise going to its co-op play, comic-book fan service, and Gotham set pieces.

Warner Bros. says the expansion goes on sale September 18, comes at no extra cost if you own the Deluxe Edition, and arrives alongside a free update for all platforms that same day adding an Absolute difficulty setting.