Some fourth-dimension roller coasters are controlled, with seats that rotate based on the spacing of two additional rails on the track.

The first fourth-dimension roller coaster to be built, X2, which opened at Six Flags Magic Mountain in 2002, was designed and patented by Alan Schilke.

[citation needed] Arrow Dynamics was the first company to produce a fourth-dimension roller coaster, lending its name to the ride style.

[citation needed] The first installation, X,[1][2] was a prototype and cost Arrow Dynamics and Six Flags itself a lot of money due to technical difficulties and design flaws.

[4] The original X coaster at Six Flags Magic Mountain reopened as X2 in 2008 with new, lighter trains and improved reliability and effects.

Later that year Inferno opened at Terra Mítica in Benidorm, Spain with an identical compact layout.

In 2011, the first ZacSpin in the United States opened at Six Flags Magic Mountain as Green Lantern: First Flight, and was themed to the DC Comics superhero of the same name.

In late 2012, S&S Worldwide unveiled a new concept called Free Spin which features a similar ride to Intamin ZacSpin.

Like with ZacSpin, Seats spin freely, but during several track sections a system of magnets forces a controlled inversion.