Massively multi-player online real-time strategy video games

Massively multi-player online real-time strategy video games, also known as "MMORTS", are video games that combine real-time strategy (RTS) with a persistent world. Players often assume the role of a general, king or other type of figurehead, leading an army into battle, while maintaining the resources needed for such warfare. The titles are often based in a sci-fi or fantasy universe and distinguished from single or small-scale multi-player RTSes by the number of players and common use of a persistent world, generally hosted by the game's publisher, which continues to evolve even when the player is not currently playing.

Unlike MMORPGs, the MMORTS genre is still in its infancy with only a few active games, none of which have come from a large publisher. Vibes, a French developer, created the first MMORTS, Mankind, in 1998. Mankind defined what the MMORTS persistent nature means. Even when players are not online, their mines extract ores, factories create equipment, ships continue commerce, and combat units continue to do battle.

Current problems
There currently exists a large problem in dealing with offline players. While MMORPG video games typically have a user's character disappear from the game world upon logout, the same idea can not apply to an MMORTS video game. Most MMORTS titles place the player as the leader of some sort of nation-state, whose disappearance would not make sense. Therefore, when a player logs out, the nation would be largely unguarded. Developers have been trying to compensate for this problem with advanced artificial intelligence to control a player's army, restrictions on destructive acts against offline users, and placing the player in control of a handful of units rather than an empire.

MMORTS video games must also deal with resource competition. In a single player real-time strategy, resources are mostly limited. The genre almost forces the game designers to use an unlimited resource system as in Total Annihilation, but this forces each successive new player to have to build more quickly than the last. A possible solution is a periodic server-reset of resources allotted to players, however, even this solution has its drawback as more experienced players will often feel that the game is cheating them for playing well.

MMORTS titles also poses several technical problems. Because the player controls not just an avatar but tens if not hundreds of units simultaneously, this puts an enormous price tag on bandwidth if the level of interaction is to compete with modern single or multi-player RTS video games. Most MMORTS titles reduce the level of simulation that needs to be synced with the server which puts serious limitations on the types of simulation that can be performed. The limitations include limited view rules such as radar and terrain blocking algorithms, limited physics simulations such as artillery arcs and shock waves, limited air and undersea combat. Simulation has to rely on simple mechanisms to stay in budget which by the player of the RTS genre might be considered outdated.

Due to the independent nature of MMORTS genre, developers have generally struggled in creating effective path-finding algorithms, with some games eschewing basic collision detection in their path-finding algorithms.

Additionally, independent game developers cannot afford to produce high quality graphics which generally means the genre fails to appeal to the wider gamer demographic, instead, most games focus on a smaller niche which is attracted to the genre due to its gameplay value. Recently, some MMORTS titles have been announced which boast highly improved graphics.