In strategy computer games, of both the turn-based and real-time varieties, a build order is a linear pattern of production, research, and resource management aimed at achieving a specific and specialized goal. They are analogous to chess openings, in that a player will have a specific order of play in mind, however the amount the build order, the strategy around which the build order is built or even which build order is then used varies on the skill, ability and other factors such as how aggressive or defensive each player is. Often, the name of a build order usually reflects two key aspects therein: The desired goal of the entire build order. The key management decisions involved in the build order. Evidence of this can be found in the following examples: Six-Pool Rush (StarCraft) – Six-Pool being the management decision (build a Spawning Pool immediately after reaching supply level 6), rush implying production of zerglings quickly. 4 Warp Gate Push (StarCraft II) – opening in which the goal is to have a Warp Gate and 4 gateways and then push (attack the enemy). Rule of Ten (Warhammer 40,000: Dawn of War) – Ten being the desired production goal of infantry units. Oranos 4:30 (Age of Mythology: The Titans) – 4:30 being the desired time to reach tech level 2. 4ES (Company of Heroes) - 4ES standing for 4 Engineers and a Sniper (a unique American opening); Fast Armored Car (Company of Heroes) – the objective being to get an Armored Car before the opponent has reached the same tech level. Riflestall (Company of Heroes) – the objective being to use the power and flexibility of Riflemen squads to hold off the opponent before pulling out higher-tech units. Piospam (Company of Heroes) – the objective being to produce large numbers of Pioneers and nothing else, until higher tier. Expansion first (generic): start by creating a new economic base, prioritizing your economy output rather than defensive or offensive units. This is usually easily countered if your opponent if going for an early-aggression build order. Strategy computer games typically offer a player many choices in which structures to build, units to train, and which technologies to research. Each technology that a player researches will open up more options, but may or may not, depending on the computer game the player is playing, close off the paths to other options. A tech tree is