MMO

MMO stands for massively multiplayer online game. It refers to a genre of online video games in which a large number of players interact within a persistent virtual world accessible over the internet. Worlds continue to evolve even when a player is away, and players influence the game through exploration, cooperation, competition, and in-game economies.

Most MMOs are MMORPGs—massively multiplayer online role-playing games—where players create characters, select a class or role, and undertake quests, combat, and exploration to gain experience and equipment. These titles typically include PvE content, PvP modes, group dungeons, and large-scale events, with social systems such as guilds, chat, and trading networks forming a central part of the experience.

Technical architecture usually relies on centralized servers or shards that host many simultaneous players. Worlds feature scalable economies, virtual currencies, item trading, and crafting. Payment models vary: some require a subscription, while others are free-to-play with microtransactions or hybrid arrangements.

History and evolution: early text-based MUDs laid the groundwork, followed by graphical MMOs in the 1990s. EverQuest and Ultima Online helped establish core mechanics of persistence and social interaction, while World of Warcraft popularized the genre with broad accessibility and ongoing live updates. Recent titles emphasize ongoing content delivery, cross-platform play, and extensive endgame systems.

Variants include social MMOs focused on virtual communities (for example virtual worlds), sandbox MMOs that stress player-generated content, and browser-based MMOs that run in lightweight clients. MMOs remain a major segment of online gaming, reflecting enduring interest in shared virtual spaces and cooperative play.