MOBA games are a genre of multiplayer games that became popular thanks to a custom map for the famous Warcraft 3 strategy called Defense of the Ancients. In it, two teams of five players fight on a map with three roads and try to destroy the enemy base.
Gamers liked this custom so much that some developers decided to make separate MOBA games based on it: now the most popular are DOTA 2, League of Legends and Heroes of the Storm (which only took the concept). You can also highlight SMITE - the first 3D MOBA.
This list contains all multiplayer online games in the MOBA genre, regardless of the year of release.