Avalanche Studios Group is a Swedish video game developer and publisher based in Stockholm. It is a parent company that includes Avalanche Studios, Expansive Worlds, and Systemic Reaction. Founded by Linus Blomberg and Christofer Sundberg in March 2003, Avalanche Studios focuses on developing open world projects and bases them on their proprietary Apex game engine (formerly known as Avalanche Engine). The company is best known for developing the Just Cause and theHunter game series.

Formed after the collapse of Rock Solid Games, the studio gained early success with the first Just Cause title. The team then began Just Cause 2's development, but the company suffered from financial problems due to the cancellations of two contracted projects. Despite missing the release window twice, Just Cause 2 was both a critical and financial success for Avalanche Studios. The company then opened a studio in New York City to work on Just Cause 3, while the Stockholm team began working on Mad Max in collaboration with Warner Bros. Interactive Entertainment. The company announced two titles in 2017, Rage 2 with id Software and a self-published title named Generation Zero. Nordisk Film acquired the company in 2018, having invested in it the year prior.

A casual gaming subsidiary, Expansive Worlds, was established in March 2010 to work on theHunter series. The company aims to begin self-publishing new original intellectual properties in the future. In addition to the office in Stockholm, the company has offices in Malmö and Liverpool.

Avalanche Studios was founded by Linus Blomberg and Christofer Sundberg in 2003. Prior to the establishment of the studio, Sundberg had worked in video game publishing as well as FIFA Soccer for Electronic Arts. Both of them joined Paradox Interactive, a video game publisher that had published games such as Europa Universalis. Eventually, Sundberg and Blomberg left and founded their own company called Rock Solid Studios during the second quarter of 2001. The company partnered with Conspiracy Entertainment to develop a video game adaptation of Tremors, a movie series from Universal Pictures. Titled Tremors: The Game, it was set to be released for personal computers, PlayStation 2, Xbox, and GameCube in 2003. During that period, another Stockholm-based video game development studio, Starbreeze Studios, announced that they would acquire Rock Solid. The agreement between the two companies was ultimately broken by Starbreeze, and the acquisition was stopped. In addition, Universal decided to cancel Tremors: The Game, which led Rock Solid to declare bankruptcy. With the failure and collapse of Rock Solid, Sundberg and Blomberg became unemployed and in debt. They eventually decided to start over in 2003, establishing Avalanche Studios with six other employees. Reflecting on the founding in 2015, Sundberg stated that the studio was born in "pure chaos", and attributed their failure with Rock Solid to trusting "the wrong people".

When naming the company, Sundberg, Blomberg and the other employees brought up a list of military code words used during World War II. They ultimately decided upon "Avalanche" as the company's name. The company worked on a prototype project called Rico: Terror in the Tropics in 2003. The project, designed by Sundberg himself, would eventually become Avalanche's first title, Just Cause. He pitched the game's concept to publisher Eidos Interactive, which was accepted. According to Sundberg, he wanted to develop a game "where you could skydive onto the roof of a car and keep on going". The game was released in 2006 for Microsoft Windows, PlayStation 2 and Xbox 360. Sundberg considered Just Cause to be the 'DNA' and 'center point of the studio', since it was the first game they developed.

Following Just Cause, Avalanche began to provide technical assistance to theHunter. Originally developed and published by Emote Games, the franchise was acquired by Avalanche on 18 February 2010. As theHunter is an online-activated game, Avalanche established a subsidiary studio called Expansive Worlds on 24 March 2010 to provide support to the continuous development of theHunter. The new studio will also work on new online games. It was a commercial success for Avalanche, with Sundberg claiming that the title "contribute[s] quite a lot to [Avalanche's] financial success". Avalanche considered theHunter to be an experiment for them to see whether the free-to-play business model suited the company or not.

Also in development during Avalanche's work on theHunter was AionGuard and Just Cause 2. AionGuard is a fantasy video game that was ultimately put on hold. Just Cause 2 was announced in January 2008. Powered by the Apex Engine 2.0, Avalanche Studios' in-house engine, the game included several new and improved features. Originally set to be released in 2008, the game subsequently missed its target release window. In 2008, the studio suffered from layoffs; Avalanche dismissed 77 staff members after the company lost approximately US$35 million due to the loss of two contracted projects. One of them was later leaked as Arcadia, a game that once was to be published by THQ. After the incident, Sundberg claimed that the company would remain as a small studio in the future. Just Cause 2 was not released in 2009, which was regarded as "a bad year for most companies including ourselves" by Sundberg. In May 2009, 20 more employees were laid-off. Despite Avalanche's layoffs, development of Just Cause 2 was completed, and the game was launched in March 2010 for Microsoft Windows, PlayStation 3 and Xbox 360. Upon release, Just Cause 2 was proven to be more popular than its predecessors; over 2 million players played the game's demo, and over 6 million players purchased the final game. As the game did not ship with any multiplayer feature, a multiplayer PC mod, which can accommodate more than one thousands players in a single map, was created by a modder. Avalanche Studios supported the mod, made the mod official on 16 December 2013, and released the mod on Steam as free downloadable content for players who had purchased the game.

Upon the completion of Just Cause 2, Avalanche teased a new project. A new downloadable title, called Renegade Ops, was announced on 30 March 2011. The team was approached by Sega to develop a new downloadable intellectual property using the Apex Engine. Compared to their past titles, the game's production and development periods were much shorter. The game drew inspirations from 1986's Jackal, 1992's Desert Strike: Return to the Gulf and 1993's Cannon Fodder. It received generally positive reviews upon its release in October 2011.