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The Joker

Steel Hybrid at Six Flags Discovery Kingdom, Vallejo, California. Opened 2016.

By Theme Park Spot · Last reviewed November 9, 2026

Height
100 ft
Drop
95 ft
Top speed
53 mph
Length
3,200 ft
Inversions
3
Ride time
2 min
Designer
Rocky Mountain Construction

The Joker is a hybrid roller coaster in the DC Universe area of Six Flags Discovery Kingdom in Vallejo, California. Rocky Mountain Construction built it by laying its I-Box steel track on the wooden structure of Roar, a Great Coasters International wooden coaster that ran from 1999 until August 16, 2015. The Joker opened in late May 2016.

A chain lift climbs 100 feet. RCDB lists a 3,200-foot track, a top speed of 53 mph, a 78-degree maximum angle and three inversions: a step-up under flip, a zero-g stall and a barrel roll. The park calls the step-up under flip the first of its kind and mentions a wave turn. Wikipedia gives a 95-foot drop and a two-minute ride.

Two trains of six cars each carry 24 riders. The minimum height is 48 inches.

Sources

  • sixflags.com/discoverykingdom/attractions/the-joker-ride (Park page: THE JOKER, coaster in DC Universe; wood and steel; world's first step-up under flip and a breaking wave turn; introduced 2016; manufacturer Rocky Mountain Construction; 48 in. minimum height.)
  • rcdb.com/13422.htm (RCDB: Joker at Six Flags Discovery Kingdom, operating since 2016-05-30; Rocky Mountain Coasters IBox Track / Custom, hybrid; length 3,200 ft, height 100 ft, 53 mph, 3 inversions, 78 degrees; chain lift; step-up under flip, zero-G stall, barrel roll; 2 trains of 6 cars, 24 riders.)
  • en.wikipedia.org/wiki/The_Joker_(Six_Flags_Discovery_Kingdom... (Wikipedia: opened May 29, 2016 after a May 25 media preview; converted from Roar (GCI, opened May 14, 1999, closed August 16, 2015); RMC I-Box track on Roar's wooden structure; 100 ft height, 95 ft drop, 53 mph, 3,200 ft, 3 inversions, 78 degrees, duration 2:00.)

Numbers are from the ride's manufacturer and park where published; "n/a" means we have not confirmed that number yet. Spotted an error? Tell us.