Marvel Avengers Alliance was a 2012 turn-based social-network game developed by American studio Offbeat Creations and published by Playdom. It is based on characters and storylines published by Marvel Comics. The game was available as an Adobe Flash application via the social-networking website Facebook. It launched in Facebook on March 1, 2012. It was initially released as promotion for the 2012 Marvel Studios film The Avengers.

It was made available on iOS and Android devices on June 13, 2013. The game was shut on September 30, 2016.

Players control an agent of S.H.I.E.L.D. and can customize the agent by gaining experience, leveling up, and equipping their agents with weapons and uniforms obtained within the game. The player can team up with two of 166 Marvel heroes in the game, each with their unique skills and abilities. While some heroes are locked and can only be recruited on some occasions, most of them are available for general recruitment, and can be bought with "Command Points", one of the currencies that appears in the game.

Gameplay consists of turn-based fights that pit the player's agent and heroes against one or more waves of three or fewer enemies, with each character having unique attacks. There are six character classes: Blaster, Bruiser, Scrapper, Infiltrator, Tactician and Generalist. The first five classes have a specific strength and a specific weakness to one of the other classes, in a rock-paper-scissors style. Blasters have guaranteed critical hits against Bruisers and ignore their defense stats. Bruisers increase their statistics when they attack or are attacked by Scrappers. Scrappers have a second automatic attack (follow-up attack) against Infiltrators. Infiltrators gain the ability to counter enemies' attacks after attacking or being attacked by Tacticians, while the latter gain an extra turn when they attack or are attacked by Blasters. The Generalist class has no special strengths or weaknesses against other classes. Some playable heroes can switch classes during the game, and a character's class may be changed with alternate costumes. The player has access to uniforms of all the classes.

Collections are a feature used to recruit new characters to your team, most of whom were previously Villains. It was first unveiled as part of Special Operations - Cry Havok.

Collections can be completed by opening Lockboxes to collect Comic Book Covers. Collecting all eight unique Covers of the Collection will unlock the Hero.

For a limited time, Player Vs. Player (PVP) tournaments are available where the players fight to reach different tiers (Silver, Gold, Diamond, Vibranium and Adamantium). Players who placed at Adamantium tier at the end of the PvP season are awarded a new hero. PvP fighting can also be done during non-tournament times in practice mode only.

Special Operations are limited time challenges in which the player has to complete, at least, 25 tasks in order to obtain a new hero. Unique boss items can be acquired through battle, and special weapons or items are rewarded for every 5 tasks completed. The only exception has been the first Spec Ops mission, in which the player had to get 5 star mastery in all the missions.