LEGO Batman Mayhem Collection Lets Joker and Harley Quinn Take Over Gotham
LEGO Batman: Legacy of the Dark Knight is about to turn its attention from Gotham’s heroes to its most chaotic villains.
The upcoming Mayhem Collection DLC will let players take control of The Joker and Harley Quinn in a new story mission and an entirely new Mayhem Mode. The expansion arrives September 18, 2026, with the DLC launching for PlayStation 5, Xbox Series X|S, Nintendo Switch 2 and PC.
The expansion gives players a different way to experience Gotham, replacing Batman’s crime-fighting mission with robberies, destruction, graffiti, vehicle theft and battles against A.R.G.U.S. forces and Task Force X.
Joker and Harley Quinn Get Their Own Story
The Mayhem Collection begins with a new story centered on Harley Quinn’s origin.
Players start with Dr. Harleen Quinzel, before her first meeting with The Joker sets her on the path toward becoming the Harley Quinn fans know.
The story takes players inside Arkham Asylum, where Joker and Harley eventually break out and turn their escape into a chaotic celebration. From there, the pair establish a secret hideout beneath the Funhouse in Amusement Mile.
The DLC also introduces more customization options, allowing players to decorate and expand the villain hideout with Joker- and Harley-themed props.
A Love Letter to Batman: The Animated Series
One of the expansion’s biggest attractions is its connection to Batman: The Animated Series.
The developers have incorporated multiple references to the influential animated show, including cutscenes presented in a 4:3 aspect ratio, echoing the original television format. The series is particularly significant for Harley Quinn because the character was first introduced in the show.
The expansion also contains references to other Batman movies, television shows, games and comic-book stories.
One Easter egg pays tribute to Arleen Sorkin, the original voice of Harley Quinn, who died in 2023. A Gotham shop called “Sorkin’s Gems” carries her name as a nod to the performer whose voice helped define Harley’s early identity.
Mayhem Mode Turns Gotham Into a Playground
The biggest gameplay addition is Mayhem Mode.
Players take Joker and Harley through repeatable, time-limited runs across a locked-down section of Gotham’s North Island. The goal is to cause as much chaos as possible while completing activities and making it back before time runs out.
That can include:
- Robbing shops
- Smashing ATMs
- Destroying vehicles
- Painting graffiti
- Fighting A.R.G.U.S. agents
- Battling Task Force X
- Collecting LEGO studs
The studs earned during these runs can then be used at the villain hideout for permanent upgrades, customization items and new outfits.
Joker and Harley Bring a Different Combat Style
The developers also wanted the two villains to feel different from the heroes in the main campaign.
Joker and Harley retain familiar abilities, but the DLC places greater emphasis on ranged combat and gadgets. Both characters can move while using their ranged weapons, creating a faster run-and-gun style designed around the constant movement of Mayhem Mode.
That makes the pair particularly suited to fighting groups of enemies while moving through Gotham.
The official DLC description also confirms that Joker and Harley have their own abilities, gadgets and takedowns.
Build a Villain Crew
The expansion adds another unusual system through a character called Henchmaster, who originally appeared in Batman: The Joker War Zone #1.
As players explore Gotham, they can rescue Arkham inmates and have Henchmaster train them. Those characters can then be assigned to a customizable crew and summoned to fight alongside Joker and Harley.
It gives the DLC another progression layer beyond simply completing missions and destroying the city.
What’s Included in the Mayhem Collection?
The Mayhem Collection includes a new story mission starring Joker and Harley Quinn, the new Mayhem Mode and a Sinister Pack. The Sinister Pack adds seven new suits for the game’s original playable characters, a new Batmobile and additional Batcave customization content.
The DLC is included with the Deluxe Edition, while the base game is required to play it. Xbox currently lists the Deluxe Edition for Xbox Series X|S and Xbox Cloud Gaming, while official game information confirms the Mayhem Collection’s broader September 18 release across PS5, Xbox Series X|S, Switch 2 and PC.
The base game itself features Gotham’s open world, seven main playable characters, more than 100 suits, more than 20 vehicles and more than 250 Batcave props and trophies.
When Does LEGO Batman Mayhem Collection Release?
The LEGO Batman: Legacy of the Dark Knight Mayhem Collection releases September 18, 2026.
For Batman fans, the expansion offers a notable change of perspective: instead of protecting Gotham, players get to tear it apart as two of DC’s most recognizable villains.
With Joker, Harley Quinn, Arkham Asylum, Amusement Mile, animated-series references and a dedicated chaos-focused game mode, the DLC is designed to give Gotham’s villains their own LEGO-sized legacy.
