From Liquipedia StarCraft Brood War Wiki
The term metagame literally means 'beyond the game' and refers to any planning, preparation, or maneuvering that a player does outside of actual gameplay to gain an advantage. The metagame has three major branches, which contain some overlap:
- Preparation done before a match to exploit current trends in StarCraft.
- Preparation done specifically to exploit an opponent's or map's style of play.
- Strategic decisions designed specifically to exploit a player's reaction or weakened mental state in the future. These are also known as 'mind games' or 'psychological warfare'.
Exploiting StarCraft Trends
This technique involves preparation based on assumptions made from observing the current state of the game. Although tracking the development of a game as complex as StarCraft is difficult, it is possible to understand the general development of StarCraft gameplay and prepare and adapt your game accordingly. An example of this is how while Terran players always opened 2 Barracks in 2005, modern Zerg players now often deal with Vultures, Wraith and Valkyries.
Big Impact Examples
The following builds are examples of a great strategic shift that forever changed the match-up and forced the opposing race to devise counter strategies or lose.
- iloveoov developed and standardized builds such as the 2 Rax FE (vs. Zerg) and 1 Rax FE.
- sAviOr developed and standardised 3 Hatchery Muta, the only time Zergs ever retained a strategical advantage for a long period in ZvT.
- Nal_rA developed, and Bisu standardised the Protoss Fast Expand vs Zerg.
- Flash pushed Terran into the modern age by replacing the outdated 4 Factory Expand with an updated Double Armory build previously used by iloveoov.
Smaller Scale Examples
The most frequent metagame shifts are between builds that try to counter each other without revolutionizing the match-up itself. While big impact strategies like the above happen once every few years, these smaller shifts usually happen at least a few times a year. It is these strategies that make up the regular and everchanging metagame because of their frequency. However, big shifts have also been historically slow to become popular and thus it was often only the original creator and a select few players that extensively used that strategy until it gradually caught on. In some cases, like with sAviOr's 3 Hatchery Muta, it took over a year and a half to become popular.
On the other hand many smaller metagame shifts catch on and become popular very quickly, thus forcing the other race to devote all their efforts to figuring out counters. These don't radically change how the match-up is played but just give one race a temporary strategical advantage.
One particular example of smaller scale metagame shifts is the PvZ record on Destination. For a time Protoss enjoyed a sizable win percentage, but then Zerg suddenly figured out a new build that more than adequately countered the Protoss standard and consequently won 13 games in a row. Then once Protoss figured out a counter to that build and won 11 out of the next 15, and so on. While the overall record eventually solidifed at an even 50%, PvZ history on that map was dominated by different streaks built from strategical advantages and disadvantages.
An excellent example of metagame development in action (again in PvZ) is Return of the King. When the map was first introduced in the Incruit OSL, Zergs enjoyed a large advantage, going 5-0. However, in the subsequent Batoo OSL, the trend completely reversed itself. Of 10 games played during Batoo, Protoss won 9 of them.
These strategical shifts, while best illustrated by Destination, were part of a long battle from 2007 into 2009 where each race constantly tried to one-up the other strategically.
- Early on Zergs countered the popular +1 Speedzeal with a greedy 4 Hatch before Gas build, using scourge to neutralize Corsairs and a quick +1 armor and lurkers to counter Zealot timing attacks.
- However with this build Zergs had a difficult time countering the Corsair/DT build and other harass based builds due to the late scourge. Thus they eventually switched over to what became the very popular 3 Hatch Scourge into Hydra, which neutralized any early Corsairs, Shuttle, and DT harass completely while obtaining a strong midgame Hydra army.
- The 3 Hatch Scourge into Hydra had a weakness to stronger timing rushes that Protoss were not slow in exploiting. From the necessity of countering this build the +1 Zealot/Archon timing attack arose, often ending games with the one decisive blow.
- After losing many games to this build Zergs countered with the 5 Hatch Hydra into Muta build along with improving their early defense by making building walls to cover their sunkens. Now Protoss had to face a very scary midgame Hydra army that could instantly snipe any Templars, the only unit preventing the mass of Hydras from running over the Protoss.
- In response to this build Protoss ceased doing early timing attacks, instead choosing to apply pressure with Corsairs, Zealots, and DTs in a more balanced, defensive build that protected Templars from being sniped.
At any given point of time one of these builds would have been popular for each race and that state would be known as the current metagame. The majority of players were expected to do the popular build for their race, although oftentimes someone would attempt to counter the current metagame by doing a different build, whether it be an old one or a new idea.
Exploiting Map or Player Styles
Build preparation, when done for a specific opponent or map, is another form of metagaming. In analysing an opponent's past gameplay strategies, a player may be able to prepare strategies that will allow him or her to later out maneuver and outplay his or her counterpart. For example, if a certain player is known to have an affinity for using a certain strategy, or is known to strongly favour a certain style of play, his or her opponent may sometimes choose to execute a build that will completely counter it. This style of play too is often considered to be psychological in nature as well, especially since the preparation for the game clearly takes into account an opponent's tactical strengths and weaknesses.
All in builds like the Zerg 5pool are used to unnerve opponents and thereby gain a mental advantage.
This refers to the psychological struggle which occurs between players at the highest level, a tussle that takes place parallel to the tactical, in-game battle itself. A very fluid idea, this term encompasses decisions made by players that are not taken solely for in-game tactical or strategic reasons but rather to alter the mental status of his or her opponent.
It is most clearly seen in best of series games between players who know each other well, since in such a situation, the players' past records and games no doubt affect them heavily as they prepare for the said series, and it is at this level of play that carefully prepared builds are often most effective.
Psychological warfare can also be utilised in the course of a game. A player could choose, for example, to show an opponent's scout fake technology - buildings or units he or she does not plan on using, and then use another line of technology entirely, or mass a completely different type of unit. If his or her opponent takes the bait and prepares for the non-existent build, the player could end up quite far ahead tactically.
- In game 1  of their OSL finals series iloveoov used the Sparks Terran rush to catch July off guard and win early. oov knew that July would have tried to construct an elaborate strategy to win on the previously Terran favored Cultivation Period so oov decided to set the pace and disrupt July's plan with a fast timing attack. This loss shook up July so badly that he ended up making uncharacteristic mistakes in the next two games and dropped out 0-3.
- In game 3  of the Shinhan Bank 3 OSL finals between sAviOr and Nada, sAviOr infested Nada's Command Center as he had won the game. This visibly shocked Nada and threw off his concentration. In the next game sAviOr made a game deciding move and Nada reacted quite poorly to it, resulting in a 3-1 win for sAviOr.
- Prior to the 2008 Bacchus OSL finals between Flash and Stork, Flash had just beaten Stork 3-2 in the Gom Starleague Invitational using upgraded Goliaths backed with a flowing economy to counter Stork's previously successful Carrier/Reaver combo. However in the OSL finals, Flash instead did 3 very aggressive builds designed to catch Stork off guard. Stork had used greedy, expand heavy builds that could defeat Flash's fast upgrade builds but doing so made him weak to the hyper-aggressive play that Flash instead showed, resulting in a 42 minute 3-0 victory for Flash. Additionally, in the pre-game interviews, Flash stated he was going to use his anti-carrier build to defeat Stork.
- In game 1 of their Best of 5 OSL finals series, July 5 Pooled Best. He knew Best planned to Fast Expand and by 5 pooling he would take control of the game and force Best out of his planned build, making all the practice time for the various ways the SKT T1 coaches felt the game might play out completely useless. July also knew that Best had very little experience in series games and would be relying heavily on sticking to his plan and playing the games out as he'd rehearsed them in practice. July didn't intend the 5 Pool to be a strategic counter but rather used it to force Best out of his planned strategy, causing him to panic and ultimately resort to an inferior build in retaliation. Although Best blocked the 5 Pool without suffering major damage his response was to attempt a very transparent Proxy Gateway strategy which July defeated with ease.
- In game 5 of the Lost Saga MSL quarterfinals between Luxury and Leta, Luxury exploited his own reputation as an unorthodox player and Leta's cautious Fast Expansion build. With the series drawn 2-2 Leta expected Luxury to attempt a Cheese against his Fast Expansion and Luxury exploited this fear by deliberately showing Leta a fast Hydralisk Den. Luxury then proceeded to do his standard 2 Hatchery Mutalisk build which won the game easily. The combination of Luxury's reputation, the pressure of a final game when drawn 2-2 and Leta's fear of cheese allowed Luxury to prevent Leta from countering the threat of Mutalisks, simply by deliberately showing a Hydralisk Den.