WB Games has officially showcased LEGO Batman: Legacy of The Dark Knight's Mayhem Collection. The DLC is scheduled to release in September 2026, arriving alongside a new version of the game for a previously unsupported platform.

At the August 2025 edition of Gamescom, Warner Bros. announced the new LEGO Batman game for current-generation consoles. However, Traveller's Tales' latest title initially skipped the Nintendo Switch 2, launching only for PlayStation 5, Xbox Series X/S, and PC on May 22, 2026. WB Games announced the Mayhem Collection a few days before confirming its September 18 release date, with the Legacy of The Dark Knight Switch 2 version launching on the same day.

Ahead of the release, WB Games shared a new Mayhem Collection trailer on August 26, offering the most substantial look yet at the upcoming DLC. The Mayhem Collection continues the game's broader approach of drawing from different eras of Batman history, with the new content particularly focused on imagery and ideas associated with Arkham. The DLC's story mission follows Joker and Harley Quinn as they orchestrate a breakout from Arkham Asylum before taking their chaos into the streets of Gotham. Both characters have their own abilities and gadgets, giving players new ways to approach the action.

The biggest addition is the titular Mayhem Mode, which puts Joker and Harley through time-limited runs across Gotham while Batman and Robin pursue them. Players must reach Amusement Mile before the timer runs out while earning LEGO studs by destroying landmarks, stores, and vehicles and completing various challenges. A.R.G.U.S. agents and Waller's Task Force X will also attempt to stop them, with Deathstroke, Killer Croc, Captain Boomerang, Deadshot, King Shark, and Polka-Dot Man among the confirmed opponents.

The roster is particularly notable because several of these characters had previously appeared in leaked information following the game's launch, when datamined files revealed Task Force X characters before their involvement was officially confirmed.

The Mayhem Collection also includes the Sinister Pack, which adds seven villain-themed outfits for the original playable cast, the Arkham Trilogy Jokermobile, and five new decorations for the customizable Batcave. Joker and Harley Quinn will also receive unlockable outfits inspired by previous Batman media, including Batman: The Animated Series and The Dark Knight Returns.

The September 18 rollout will not be limited to paid DLC, either. WB Games is also adding a new Absolute difficulty setting through a free update for all players. Positioned above the existing Caped Crusader and Dark Knight difficulties, Absolute is designed to demand greater skill, awareness, and precision during combat, giving returning players a new challenge regardless of which version of the game they own.

With the Mayhem Collection, the Switch 2 release, and a new difficulty setting all arriving on September 18, LEGO Batman: Legacy of The Dark Knight is set to receive a substantial update later this year. The new DLC also gives players their first major opportunity to step into the roles of Joker and Harley Quinn while facing off against a collection of Task Force X villains.