MapleStory is a free-of-charge, 2D, side-scrolling Massively Multiplayer Online Role Playing Game developed by the 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, many player 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 walk around in the "Maple World" and defeat monsters and develop their character's skills and abilities, as in typical 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 band in a guild to interact more easily with each other.

Like most MMORPGs, gameplay centers on venturing into dungeons and combating 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 awarded to higher-level members.

MapleStory's 2D scrolling viewpoint more closely resembles a platformer rather than the typical 3D or top-down view of other games (such as Guild Wars or Mu Online). However, the shadowing in the game may cause one to think that it might be 3D.[citation needed] The controls for the game are executed using the computer keyboard and mouse. The keyboard is used for many game functions, and much of it can be rearranged to suit users' 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. There is limited functionality in transferring items between characters of the same world; many players use "mules" that hold the player's items and Mesos.[citation needed] The ability to transfer entire characters between worlds was added in December 2007 to GlobalMS. This feature has restrictions such as a maximum transfer of 1 million Mesos and the inability to transfer to the newest world.

New players are sent to Maple Island, a floating island specifically designed to be beginner-friendly. Unlike many other MMORPGs, players in MapleStory cannot choose a job when they create the character. Rather, every character starts with the job Beginner until they meet the requirements to complete the first job advancement.

At either level eight or ten, depending on the desired class, the player can willingly choose to complete the first job advancement and acquire a new class as a Warrior, Magician, Bowman, Thief, or Pirate (though Pirates are only available in KoreaMS). The Magician class is the only class that can be chosen at level eight. Further class progression is only allowed within the scope of the first class advancement chosen. There are three to four classes (depending on what version the user plays). Some players, however, decide to not get a job and become "permanent Beginners." Permanent Beginners may chose to leave Maple Island but those that decide not to, are refer to as Islanders.

Players can form Guilds with other players. Guild creation costs a certain amount of Mesos, depending on the version being played. Guild extensions, 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. The player attempts to avoid enemies and obstacles that can knock them off the platform. Skills and Abilities that increase jumping distance or speed do not have any effect during these quests.

Since MapleStory is free, the developers of MapleStory introduced the Cash Shop to generate revenue. This is a virtual shop where players can buy items using real money, so called microtransactions. Most Cash Shop items expire after a certain period of time. Pets, modeled after animals such as monkeys, dogs, cats, bunnies, pandas, and pigs, follow the owner around and can be equipped to pick up spoils dropped by enemies.

The Free Market is a place set aside for people who wish to sell their items amongst other players. Miniature shops can be set up in this area in which people can browse their stock. Shop permits, required to set up a shop, are only available through the Cash Shop. There are two types of store permits: a standard store, which requires the presence of the player, and the hired merchant which does not require the presence of the player but requires additional cash shop money to use this feature. The hired merchant store is only available in time periods of 24 hours, one week, or two weeks. Conversely, the standard store lasts ninety days but only works with the presence of the user. One can meet with players located in other towns, provided the town contains a Free Market entrance. However, one cannot use the free market to travel between towns.

RMT (real money trading) between players is prohibited in MapleStory, and will result in a ban. This includes trading mesos (ingame currency) with NX Cash Items (items bought with real money).