One major difference between Prophecies and the later chapters is in the acquisition of skills. All chapters utilize skill trainers, which will teach your character a new skill at a cost which starts out low Maple Story mesos. However, Prophecies alone offers new skills and spells as rewards for normal quests throughout most of the game. These free skills are a major reason why players will create their warriors or monks in the Prophecies chapter rather than the later chapters.
The two tribes in Factions, the Kurzicks and the Luxons, each have an area for players to group together into teams of four. Each Alliance Battle randomly groups three of these teams from each side into a cooperative group of twelve, who work together to defeat the opposing group by obtaining more kills and controlling more shrines in the huge arena. All chapters allow you to use AI-controlled henchmen to fill out your group; but Heroes allow you to manually use their skills and edit their builds and attributes, as well as individually assign them positions on the map. Heroes are extremely useful for PvE, and even have their own PvP arenas called Hero Battles, which allow two human players to fight each other using teams of four: one human player and his or her three Heroes.