The Roman naumachia. Source
The Romans in their re-enactment of naval battles in the naumachia were perhaps the first peoples to simulate battles on a scale resembling reality. The first known naumachia was held by Julius Caesar in 46 BC as a celebration of victory in battle, as became typical of the grandiose (and costly) events. Caesar had an artificial lake dug to create an arena large enough to hold warships and allow them to maneuver. He then stocked the lake with warships manned by 6000 prisoners of war and made them fight to the death. Later naumachiae were larger and grander. Beginning with the reign of Nero, massive amphitheaters were constructed for their purpose. Typically, the combatants would be assigned identities of contemporary maritime powers, for example the Egyptians and Tyrians during the time of Caesar. Unlike the small-scale skirmishes of gladiators and wild beasts in the smaller Roman amphitheaters, the naumachia was performed on a grand scale, worthy of the historical battles it sought to replicate.
A modern incarnation of the Roman amphitheater: Beaver Stadium at Pennsylvania State University. The stadium has a capacity of 107,282, making it the fourth largest in the world. Source
The spectacle of modern sports bears many resemblances to that of ancient arenas. Fans flock in the tens of thousands to arenas to see teams representing their state or nation defend their glory, and hundreds of thousands more watch on television. Sport uniforms are often as colorful as ancient military uniforms, and many sports can draw blood. The rhythm of the sounds of helmets clashing and men grunting in American Football is primal and chaotic like the sounds of battle and the teams display a level of organization and training similar to a military squad. Sports such as football are very much a celebration of battle, although in a disguised and toned-down form.
A crowd gathers to watch a Starcraft tournament in South Korea. Source
Today, fans of real-time strategy (RTS) games celebrate the art of battle with a level of interactivity and on a scale beyond anything seen before. RTS games situate the player in a bird's eye view of the battlefield, where he orchestrates the collection of resources, construction of military and technological facilities, and the movements of troops. The games can simulate vast battlefields with hundreds to thousands of troops, ships, and vehicles, beyond the scope of the naumachia or modern professional sports. Some RTS games are ultra-realistic simulations of ancient armies while others feature futuristic armies with advanced technology and capital ships. The genre is to date the most flexible media created for simulating battles for entertainment.
A Korean Starcraft match featuring "The Emperor", Lim Yo-Hawn, AKA SlayerS_`BoxeR`
A television commercial featuring Boxer, who at his prime received an annual salary of approximately USD $300,000
When Blizzard Entertainment's Starcraft was released in South Korea in 1998, it took the country by storm and the popularity of the game and its 2010 sequel, Starcraft 2, has only increased since. South Korean fans fill arenas to see their favorite players compete in televised tournaments for glory and monetary rewards. Korean Starcraft progamers can achieve as high of a status as celebrities and professional sports players can here. Appreciation of the game is not limited to males; female fans are abundant in the stands and can even be seen crying when their favorite player loses a decisive battle during the game. Watching players duke it out with massive armies featuring capital ships and other futuristic and alien military technology with thousands of fans cheering in the stands must be very much like attending a modern naumachia. Even non-players can enjoy watching RTS games because of how visual the action is.
A demonstration of the virtuous control of mouse and keyboard required to play Starcraft professionally.
Starcraft and other 'e-sports' are achieving increasing mainstream acceptance in the west, and I believe that it is only a few years before we see televised tournaments in The States like those currently held in South Korea. A number of progamers from the western nations including America, Canada, and Germany compete in Starcraft 2 tournaments in Korea and are among the best players in the world. Matches in western-based tournaments such as the TSL receive tens of thousands of viewers over the Internet and have cash prizes in the tens of thousands of dollars.
For recent Starcraft 2 matches, I recommend GOMtv's coverage of the GSL. GOMtv's casts feature English commentary from Tasteless and Artosis, who are probably the most entertaining commentators I have ever heard. The Code S final from the last season of GSL featuring oGsMC and ST_July, both considered among the best players in the world by many, can be found here. Skip to ~44 minutes for the actual match, but I included the video because it has good depictions of the whole spectacle surrounding professional gaming in Korea.