LEGO Batman: Legacy of the Dark Knight Details Mayhem Collection DLC

LEGO Batman: Legacy of the Dark Knight is officially handing the keys of Gotham to the bad guys. The game's new "Mayhem Collection" DLC is scheduled to arrive on September 18 for Xbox Series X|S, developer TT Games announced on Monday. For players who have spent the base game building Batman's noble legacy, the expansion offers a chance to immediately tear it down piece by plastic piece.

Writing on the official Xbox Wire, TT Games Design Director Jimmy Sedota detailed how the expansion shifts focus to DC's premier chaotic couple, The Joker and Harley Quinn. Instead of defending Gotham, players will spend their time causing systematic municipal damage, drawing heavy inspiration from "Batman: The Animated Series." It is a nostalgic pivot for a studio that has built an entire empire on letting players smash digital toys.

The details

• Release date: September 18, 2026
• Platform: Xbox Series X|S
• Key characters: The Joker and Harley Quinn
• Base game price: $69.99

What's in the box?

The expansion serves as a love letter to the landmark 1990s cartoon created by Bruce Timm and Paul Dini. According to Sedota, players will see direct nods to the television format, including cutscenes presented in a classic 4:3 aspect ratio. The campaign details Harley's origin story, starting with her days as Dr. Harleen Quinzel in Arkham Asylum before her eventual breakout with The Joker.

The DLC also features a tribute to the late Arleen Sorkin, the original voice actor for Harley Quinn who passed away in 2023. Players can find a Gotham City jewelry shop named "Sorkin's Gems" as an in-game memorial.

Once out of Arkham, the duo sets up a customizable hideout beneath the Amusement Mile funhouse. Here, players can recruit Arkham inmates and have Henchmaster—a character pulled from Batman: The Joker War Zone #1—train them into a summonable combat crew.

How does mayhem play?

Combat is designed to feel distinct from the Caped Crusader's standard brawling style. TT Games has emphasized ranged, gadget-heavy combat that allows both characters to move freely while attacking. The run-and-gun design is built specifically for "Mayhem Mode," a series of repeatable, time-limited runs across a locked-down North Island.

Activities in Mayhem Mode include robbing shops, smashing ATMs, painting graffiti, and fighting off A.R.G.U.S. agents and Task Force X. The studs collected during these runs can be spent back at the hideout to unlock 30 new outfits for the lead villains and various customization props.

Whether players use those upgrades to build a perfect villainous hideout or simply to find the ultimate clown outfit, the city of Gotham is about to get a lot noisier.