Ethan Crossfield 
Warner Bros. Games is expanding its latest LEGO Batman project as publishers continue using post-launch content to extend major franchise releases across platforms. The Mayhem Collection for LEGO Batman: Legacy of the Dark Knight now has an official trailer and a September 18 release date, which is also when the game will reach Nintendo Switch 2.
Switch 2 Version Joins the September Rollout
Traveller's Tales' newest Batman game was announced for current-generation consoles during Gamescom in August 2025. Despite that broad announcement, the launch version arrived only on PlayStation 5, Xbox Series X/S, and PC on May 22, 2026. Nintendo Switch 2 players were left waiting, but WB Games has now confirmed that the platform version will launch alongside the Mayhem Collection on September 18.
The simultaneous release gives Switch 2 owners access to the full game at the same time as the first major expansion. It also creates a second notable date for Legacy of the Dark Knight after its initial release on other platforms earlier in the year.
Joker and Harley Quinn Lead the New DLC
WB Games' August 26 trailer provides the clearest look yet at the Mayhem Collection. Its story content follows Joker and Harley Quinn as they engineer a breakout from Arkham Asylum before bringing their chaos into Gotham. Each character comes with distinct abilities and gadgets, giving the pair different gameplay identities from the game's existing cast.
The expansion continues the base game's interest in multiple periods of Batman history, with especially clear visual and thematic links to the Arkham era. That mix allows the DLC to build a new storyline while staying connected to familiar elements of Batman's wider media history.
Mayhem Mode Adds Time-Limited Gotham Runs
The collection's biggest gameplay addition is Mayhem Mode. Joker and Harley must complete timed runs across Gotham while Batman and Robin pursue them. Players can earn LEGO studs by destroying landmarks, shops, and vehicles, while optional challenges add further objectives before the duo must return to Amusement Mile.
A.R.G.U.S. forces and Waller's Task Force X complicate those runs. The confirmed opposing roster includes Deathstroke, Killer Croc, Captain Boomerang, Deadshot, King Shark, and Polka-Dot Man. Several of these characters had previously appeared in datamined material following the base game's spring 2026 launch, so their official inclusion resolves earlier speculation around the DLC's lineup.
Free Difficulty Update Arrives With the Paid Expansion
The Mayhem Collection also contains the Sinister Pack, which adds seven villain-inspired outfits for the original playable characters, the Arkham Trilogy Jokermobile, and five decorations for the customizable Batcave. Joker and Harley receive additional unlockable appearances drawing from earlier Batman productions, including Batman: The Animated Series and The Dark Knight Returns.
Players will also receive a free update on September 18. It introduces Absolute difficulty, positioned above the existing Caped Crusader and Dark Knight settings. WB Games describes it as a tougher test of combat skill, awareness, and precision, making the update relevant to players who already own the game regardless of platform or edition.
Key points
- The Mayhem Collection launches on September 18.
- LEGO Batman: Legacy of the Dark Knight also reaches Switch 2 that day.
- Mayhem Mode features timed Joker and Harley Quinn runs through Gotham.
- A free update adds Absolute difficulty for all players.
Confirmed September content
| Release | Date | What it includes |
|---|---|---|
| Mayhem Collection | September 18 | Story mission, Mayhem Mode, Sinister Pack, and Batcave additions |
| Switch 2 version | September 18 | LEGO Batman: Legacy of the Dark Knight on Nintendo Switch 2 |
| Free update | September 18 | Absolute difficulty for all players |
Expert View
The September plan gives Warner Bros. Games a coordinated way to broaden the game's audience while rewarding existing players with fresh content. Bringing the Switch 2 edition out alongside the expansion avoids leaving that platform several content cycles behind, while the free difficulty update offers a reason for returning players to revisit the game. For the franchise, the combination of recognizable villains, Arkham-inspired material, and references to earlier Batman media keeps the DLC positioned as a broad fan-service release rather than a single-era tie-in.
