The Joker

The Joker opened at Six Flags Great America on May 27, 2017, one of three nearly identical S&S Worldwide "Free Spin" coasters the chain rolled out that same season at Six Flags Over Texas and Six Flags New England, plus a fourth later at Six Flags Great Adventure. Announced in September 2016 and built adjacent to Batman: The Ride, it continued the park's decades-long tradition of pairing new coasters with DC Comics characters, following Batman (1992), Superman (2003), and Dark Knight (2008).

Riders board individual cars seated in facing pairs, which climb a 120-foot vertical lift hill before a system of onboard magnets and track-mounted linear induction motors take over, inducing controlled spins through a series of raven turns — drops that exceed 90 degrees as the car descends between three vertically stacked layers of track. Because the spins respond to how riders shift their weight and rock the car, no two rides play out exactly the same way, a deliberate design choice distinguishing it from coasters with fixed, predictable inversions.

The Joker's opening weekend was disrupted when a passing storm forced the park to briefly halt riders atop the 120-foot lift hill and call in emergency services as a precaution, delaying the ride's full public debut by a day. Since then it has operated as one of the park's more unpredictable thrill credits, its outcome varying rider to rider in a way few other coasters in the lineup can claim.