Skullgirls is a fighting game developed by Lab Zero and primarily published by Marvelous and Autumn Games. Since its initial release in 2012, it has received two free extensions, Skullgirls Encore and Skullgirls 2nd Encore and while its roster initially consisted of an all-female cast of 8 characters, 6 more characters were added, 5 being developed thanks to the game's Indiegogo crowdfunding campaign, including 2 male characters. At its release, Skullgirls was developed by Reverge Labs, but the team that created the game split off from the company to form Lab Zero. In Japan, the game is published by Arc System Works. On Nintendo Switch, the game is published by Skybound Games.

Skullgirls takes place in the Canopy Kingdom, inspired by 1940s America, in which corruption and conflict runs rampant. Once every seven years, an artifact called the Skull Heart appears, granting the wish of one woman. However, if the Skull Heart is used by a woman with impure intentions, it will control her, turning her into a destructive monster called the Skullgirl. Not once has anyone used the Skull Heart without falling to its curse. The game follows the stories of 14 characters on their way to face the Skullgirl and retrieve the Heart, be it for the greater good or simply their own gain.

The game is a tribute to Marvel vs. Capcom 2 and its mechanics are intended as a more polished version of the classic fighting game title, with some original ideas. In a standard player vs. player match, each player controls one character out a chosen number of one to three characters which they can switch to at any time. They can also call their inactive characters to perform assist attacks. Like most Marvel vs. Capcom-inspired games, Skullgirls is fast-paced and features long, complex combos based on animation cancels. It introduces a burst system which allows players to break their opponent's combo if it becomes too long.

Skullgirls features a 'dark deco'-inspired art style mixed with some horror themes and a jazz and rock soundtrack consisting of 28 tracks. In 2013, the game set the Guinness World Record Gamer's Edition record for most average frames of animation per character in a video game, reaching 1,439 frames per character and 11,515 frames total for its initial eight-character roster.

In February 2013, Skullgirls came in second in a crowdfunding event organized by fighting game website Shoryuken to decide what would be the final game featured on the EVO 2013 line up, with all proceeds sent to the Breast Cancer Research Foundation. Skullgirls raised over $US 78,000. While it was not featured as an EVO main game, EVO organizers supported the game's side event by providing prize money and advertisement.