Sandbox Massively Multiplayer Online (MMO) games are typically developed to give as much freedom and creative control to players as possible. Much like other MMOs, these are persistent environments and usually have a digital world in which characters can be made. The major element that sets a sandbox MMO apart from other types, however, is the level of freedom and control that players are given; they are allowed to make the game into what they want it to be. In these types of MMOs, characters often have a great deal of freedom to advance in various ways and players are left to find their own way in the world.
There are varying degrees of freedom that can be allowed in a sandbox MMO, and some proponents of this sub-genre prefer it to be absolute. This would require that players are able to make characters and interact with the world in any way they see fit. The creation of new content and environments within the game and character advancement along undefined routes would all be welcome aspects for any sandbox MMO. Many of them, however, do not have quite this level of freedom, though they can come close to it.
In a sandbox MMO, characters often use an advancement system that is similar to other games, but is more “open.” Many games allow players to choose a “class” for a character that defines their role within the world. A sandbox MMO, however, typically allows a player to make a character and then defines his or her role through gameplay and choices made while playing.
Similarly, the freedom to explore and experience a game in any way the participants see fit is a major element within a sandbox MMO. While there may still be quests and missions for characters to complete, the way in which they are done can be far more open to creative thinking. Players are typically free to come up with an idea and then try to do it within the game. Some people may prefer to find large monsters and slay them, while others are content to build houses and player cities that are then populated by the various characters within the game. This is where the name comes from, as players are meant to be free to do what they want, like they are playing in a sandbox.
In contrast to this, “theme park” MMOs, feature characters that are often much more restrained. Much like an actual theme park, there are often “attractions” or events that players are directed toward in their game experience. Roles for characters are usually more defined and the developers exert more control over the world of the game. Neither type of MMO is superior to the other; they are simply designed with different philosophies.