Build Orders

What Is a Build Order?

A build order is the specific sequence of structures, units, and upgrades you make during the opening minutes of a StarCraft II game. Every action is tied to a supply count. “14 pool” means you drop a Spawning Pool when you hit 14 supply. “16 Hatch” means your natural expansion goes down at 16.

It sounds rigid, and it is. That’s the point. The first three to four minutes of an SC2 game are almost entirely scripted, even at the highest level. Pro players drill their openers until the keystrokes are automatic, because those early decisions compound. Being 10 seconds late on your first Gateway means your Warp Gate finishes late, which means your first round of Stalkers is late, which means you might just die to an early push.

Why the Opening Minutes Matter

SC2 is a game of snowballing advantages. A worker lead at the 4 minute mark translates into more production at 6 minutes, which translates into a bigger army at 8 minutes. The reverse is true too. Lose two workers to a Reaper you weren’t ready for and your whole game plan shifts. You’re playing from behind, trying to stabilize instead of executing your strategy.

A good build order gives you a plan. It tells you exactly when to take gas, when to start production structures, when to expand. Without one, you’re making it up as you go. Some players can improvise at a high level, but they still have a framework in their head. The difference between a Diamond player and a Masters player often comes down to how tightly they follow their build in the first five minutes.

Terran Openers

Terran builds revolve around the Barracks, Factory, and Starport production chain. The most common macro opener for years has been Reaper expand: you build a Barracks at 16 supply, put down a Refinery at 16, start a Reaper as your first unit, then take your natural Command Center at about 20 supply. The Reaper scouts and harasses while your economy ramps up.

From there, the 2-1-1 build (two Barracks, one Factory, one Starport) gives you a solid mid-game composition of Marines, Medivacs, and a Siege Tank or two. The Factory gets an early Reactor swap to pump Widow Mines in some variations. 1-1-1 is the other big branch, where you go for a faster Starport and get early air control or Liberator harassment. What you choose depends on who you’re facing. Against Zerg, that early Hellion/Hellbat pressure from a Factory opener can deny creep and kill Drones. Against Protoss, getting your Tank out early matters a lot more.

Protoss Openers

Protoss almost always starts with a Gateway at 14 supply, a Cybernetics Core right after, then a Nexus. The real decision comes after the Cyber Core finishes: do you go Twilight Council for Blink Stalkers or Charge Zealots? Robotics Facility for Immortals and an Observer? Or Stargate for Oracles and Phoenix?

Stargate openings are popular because Oracles give you scouting and worker harassment in one package. A Protoss who opens Oracle into double expand can get to a very strong economy if the opponent doesn’t apply pressure. The Robo opener is safer, more defensive. You get detection from the Observer and Immortals are hard to deal with for ground-based aggression. If you like to attack early, the Twilight openers let you hit a timing with Blink Stalkers around 5:30 that can end games outright against someone who over-committed to economy.

Zerg Openers

Zerg is unique because your production building is also your base. Every Hatchery produces Larvae, so expanding directly increases your ability to build units. This is why Hatch First (taking a natural Hatchery before a Spawning Pool) is the standard macro opener. You go Hatchery at 16, Pool at 18, then take gas and start your Queen when the Pool finishes.

Pool First (12 or 13 supply) is the aggressive option. You get Zerglings out fast and can put immediate pressure on your opponent while still expanding behind it. The real cheese is 12 Pool with a Drone pull, going all-in on Zerglings before you even think about economy. There’s also 3 Hatch before Pool, which is an extremely greedy opener. You take two expansions before building a Spawning Pool at all. If you don’t get scouted, you end up with an insane economy. If you do get scouted by an aggressive opponent, you probably just lose.

Reading Build Order Notation

Build order notation is straightforward once you get the format. Each line lists a supply count followed by the action. Sometimes you’ll also see a game clock timestamp. It looks like this:

The number on the left is your supply count at the moment you start that building or unit. Some guides include the game clock (like “1:42” for your Barracks), which helps you judge if you’re on pace. If a guide says Barracks at 16 supply and 0:46, and yours finishes at 1:05, you know your worker production had gaps somewhere.

How the AI Coach Analyzes Your Build

When you upload a replay, the AI analysis engine extracts every building placement and unit production event with its exact game time and supply count. It then compares your sequence against known build order benchmarks for your matchup.

The comparison is specific. It will tell you that your natural expansion went down 15 seconds late, or that you took a second gas before you needed it and floated 200 minerals at the 4 minute mark as a result. It identifies your opener (Reaper expand, Hatch first, Stargate, whatever it detects) and checks whether you executed it cleanly or deviated partway through.

Deviations are where most players leak value. Maybe you got spooked by a scouting probe and built extra units you didn’t need. Maybe you forgot your second Barracks while microing a Reaper. The coach flags these moments because they’re the kind of thing you don’t notice while playing but they cost you games over time.