Since then, it has evolved into a scare-a-thon event filled with themed haunted houses, scare zones and shows that runs over the course of select nights from early August/late September until late October/early November, inspiring offshoots at other Universal Studios locations across the globe.

The Orlando event was held at Universal Studios Florida from 1991 until 2001, after which Halloween Horror Nights moved to neighboring Islands of Adventure for 2002 and 2003.

In addition to Nazarman's and the Bates Motel film set, the new locations were in the Earthquake overflow queue and the Boneyard.

[9] Following an unsuccessful attempt to franchise the "Chamber of Chills" haunted house located within CityWalk in 1996, Halloween Horror Nights once again relaunched at Universal Studios Hollywood on October 9, 1997, running through the 2000 season.

[15] Because the September 11 attacks occurred so close to Halloween Horror Nights XI, Universal made many changes to tone down the event.

Edgar Sawyer was conceived as a demented, chainsaw-wielding horror movie buff that had been disfigured by a fire.

Eddie was ultimately removed from the event before it began, although he was still appearing on that year's logo and merchandise with the official "I.C.U."

Cindy (sometimes spelled "Sindy"), the daughter of mortuary owner Paul Bearer, was originally the icon of the event.

After several child abductions in the area, the Cindy concept was abandoned and her father Paul Bearer changed into Dr. Albert Caine, also known as The Caretaker.

Halloween Horror Nights 12, the first to be held at Islands of Adventure, featured five haunted houses, with admission set at $49.95.

[23] For Halloween Horror Nights 14 in 2004 the resort experimented with a dual-park format, which connected and utilized parts of both parks.

[26][27] In 2006, "Horror Comes Home" to the Universal Studios Florida park for its sweet 16 celebration with the four previous icons.

"Roaming hordes" replace scare zones and The Walking Dead arrive as the event icon in 2012.

[52] In 2012, Universal Studios Japan joined the Halloween Horror Nights franchise with an event themed to the Biohazard video games (known as Resident Evil in other countries).

The Walking Dead continued as the event icon and The Rocky Horror Picture Show Tribute returned.

[60] Florida's Halloween Horror Nights 24 in 2014 featured eight haunted houses and a return to the use of scare zones, absent since 2012.

[69] Universal Studios Hollywood included Throwback Thursdays as part of Halloween Horror Nights 2019.

Along with local Los Angeles 80s cover band, Fast Times, performing on select nights for the event.

[70] Halloween Horror Nights 30 was initially planned for 2020, but it was cancelled and delayed to 2021 due to the COVID-19 pandemic's impact on theme parks.

[75] By December 2023, Halloween Horror Nights was confirmed to be included for the upcoming Universal Studios United Kingdom.

These characters have included Jack the Clown, The Caretaker, The Director, The Storyteller, Bloody Mary, The Usher, Fear, Lady Luck, Chance and The Pumpkin Lord.

She was a new icon but used to serve as a "sidekick" to Jack (though there are rumours that they have a romantic relationship) in his shows (her role and look being inspired by Batman antagonist Harley Quinn[93]).

In 2007, for Halloween Horror Nights 17, Universal again licensed intellectual properties from others, in this case New Line Cinema for Freddy Krueger, Jason Voorhees, and Leatherface,[32] however, Jack the Clown was still featured.

Set in Fear's Lantern from HHN 20, each had their own special room in the house where they re-enacted famous kills.

When the event first started as "Fright Nights" at Universal Studios Florida,[94] there was simply one haunted house: the Dungeon of Terror.

[95] As the event progressed through the years, the number has increased to as many as ten different houses, as of Halloween Horror Nights 28 in 2018.

By 2014, the traditional scare zones returned with The Purge: Anarchy (inspired by the film), Face Off: In the Flesh, Bayou of Blood, and MASKerade: Unstitched.

[citation needed] However, Hollywood Horror Nights in California still has specific scare zones, that range in themes.

Many actors in these areas have props like bats, chainsaws, and fake guns, and can act like they are going to attack guests with their "weapons".

[101] It was "...a scatter-shot mashup of pop culture, popular radio and unexpectedly mature content" according to a review.