LEGO Batman: Legacy of the Dark Knight is getting a chaotic new expansion on September 18, 2026, and this time the spotlight belongs to Gotham’s most notorious villains. Warner Bros. Games and TT Games revealed the Mayhem Collection DLC during Gamescom 2026, giving fans their first look at a new playable campaign starring The Joker and Harley Quinn.
The upcoming DLC brings a major twist to the open-world LEGO Batman adventure by shifting the focus away from Batman and his allies. Instead, players will step into the roles of The Joker and Harley Quinn as they escape Arkham Asylum and unleash trouble across Gotham City. For fans who have been waiting to play as Batman’s rogues gallery in Legacy of the Dark Knight, this expansion marks a big change for the game.
At the center of the Mayhem Collection is a new villain-focused story campaign. The gameplay trailer shows The Joker and Harley Quinn causing chaos in classic LEGO style, mixing slapstick comedy, destruction, and action-packed missions across Gotham. The expansion also introduces Mayhem Mode, a new activity built around creating disorder throughout the city.
While the full details of Mayhem Mode have not yet been revealed, early achievement listings suggest there may be more depth than a simple side activity. References to Mayhem Runs and a shop operated by “Joker-Mite” hint at new challenges, rewards, and possibly repeatable gameplay built around the villains’ chaotic antics.
The DLC also includes the Sinister Pack, which adds seven new suits for the original playable characters from the base game. The exact costume designs have not been shown yet, but the pack is expected to expand customization options for players who enjoy switching up the look of their favorite heroes.
Alongside the new suits, the Mayhem Collection adds a new Batmobile, five new Batcave customization props, and 12 new achievements. These additions should give completionists and longtime players more reasons to return to Gotham after finishing the main campaign.
The Mayhem Collection launches worldwide on September 18, 2026, for PlayStation 5, Xbox Series X/S, PC through Steam and the Epic Games Store, and Nintendo Switch 2. The Nintendo Switch 2 version of LEGO Batman: Legacy of the Dark Knight also launches on the same date, with a physical edition that includes an exclusive minifigure.
Players who already own the Deluxe Edition will receive the Mayhem Collection at no additional cost. Standard Edition owners on PlayStation 5, Xbox Series X/S, and PC can upgrade to the Deluxe Edition for $24.99 / £21.99. The upgrade includes access to both the Mayhem Collection and the previously released Legacy Collection.
LEGO Batman: Legacy of the Dark Knight first launched in May 2026 and received strong reviews, with scores landing in the mid-80s on major review aggregators. Since release, TT Games has continued supporting the open-world Gotham adventure with themed content, but the Mayhem Collection stands out as the first paid post-launch expansion.
By handing control to The Joker and Harley Quinn, the DLC gives players a fresh way to experience Gotham City. Instead of stopping crime, players will be causing it, turning the familiar LEGO Batman formula upside down with a villain-led adventure full of humor, mayhem, and collectible-driven gameplay.
Nintendo Switch 2 preorders are currently available for both the Standard Edition at $69.99 and the Deluxe Edition at $89.99 ahead of the September 18 launch. For LEGO Batman fans, DC players, and anyone who enjoys open-world superhero games with a comedic twist, the Mayhem Collection looks like one of the biggest reasons to revisit Gotham this fall.
