MapleStory is a free-of-charge, 2D, side-scrolling massively multiplayer online role-playing game developed by the South Korean company Wizet. Several versions of the game are available for specific countries or regions, and each is published by various companies such as Wizet and Nexon. Although playing the game is free, character appearances and gameplay enhancements can be purchased from the "Cash Shop" using real money. MapleStory has a combined total of over 50 million subscriber accounts in all of its versions. MapleStory North America (Global), for players mainly in North America and outside of East Asia, Southeast Asia and Europe, has over three million players. In the game, players travel the "Maple World", defeating monsters and developing their character`s skills and abilities as is typical in role-playing games. Players can interact with others in many ways, such as through chatting, trading, and playing minigames. Groups of players can band together in parties to hunt monsters and share the rewards. Players can also join a guild to interact more easily with each other.

Like most MMORPGs, gameplay centers on venturing into dungeons and combatting monsters in real-time. The players combat monsters and complete quests, in the process acquiring in-game currency called "Mesos", experience points (EXP), and various items. Players can kill monsters alone, or they can form a party with up to six total characters. Loot is shared based on relative damage and level of characters in the party, more being awarded to the higher-level members. MapleStory`s 2D scrolling viewpoint more closely resembles a platform game rather than the typical 3D environment or top-down perspective of other games, such as Guild Wars or Mu Online. The controls for the game are executed using the keyboard and mouse. The keyboard is used for many game functions, and much of it can be rearranged to suit user`s needs. The mouse is mainly used to trigger non-player characters (NPCs) and manipulate items. MapleStory characters exist in "worlds" or "servers." Players are allowed to create multiple characters in each world. Each world, similar in content between each other in the same version, is split into at most twenty channels, among which characters are allowed to freely switch. The ability to transfer entire characters between worlds was added in December 2007 to GlobalMS. However, this feature has a restriction — transfer of mesos is limited to 1 million, and players cannot transfer to the newest world.

New players are sent to Maple Island, a floating island specifically designed to be beginner-friendly. Unlike in many other MMORPGs, players in MapleStory cannot choose a job when they create a character. Rather, every character starts with the "Beginner" job. When characters meet certain requirements, they can complete the first job advancement and become a Warrior, Magician, Bowman, Pirate, or a Thief. Further class progression is only allowed within the scope of the first class advancement chosen. There are four class advancements available progressingly through out the game. In addition to combat statistics, characters have "Fame". Although publicized by the game`s creators, fame serves little practical purpose besides fulfilling some quest and equipment requirements. Once characters reach level 15, they are able to raise or drop the fame of any other character once per day. A character cannot raise or drop the same character`s fame more than once per month. The maximum amount of fame a character may receive is 30,000. A ranking feature, available in certain versions of MapleStory, keeps track of players that are performing well in total ranking, job ranking, world ranking and fame ranking. Rank information is available from the region website of the player and can also be found in-game.

Players can form Guilds with other players. Guild creation costs a certain amount of Mesos, depending on the version being played. Guild extensions and emblems, which have separate costs, are also available. The purpose of a guild is to be able to find and chat with others more easily, bond with other players, promote cooperation, and battle using teamwork. Members have their guild`s name listed under their character name along with the guild`s emblem, if applicable.

There are over a hundred available quests, each with varying prerequisites; most quests may require the player to have attained a certain level or to have completed another certain quest. Most available quests require the player to retrieve a certain amount of spoils attained from monsters or to traverse an obstacle course. Some quests can be repeated, although the reward(s) and given EXP may be different from those attained during their first completion. Jump quests are a unique type of quest in which a character starts at one area of a map and uses timed jumps to get from one to another specific platform. Players attempt to avoid enemies and obstacles that can knock them off of the platforms. Skills and abilities that increase jumping distance or speed do not have any effect during these quests.