Mass Reaper opening was the go-to-build when Heart of the Swarm was just released, until other builds got more popular. Now, two barracks Reaper have become a “10 pool build”, and I will explain why.

Overview

Zerg generally goes for a Hatchery first build, while 10 pool is considered to be unorthodox. However, it is not a cheese like 6 pool, as you can transit into normal play after that without any problem. 10 pool can give you build order advantage if opponent didn’t expect that. If opponent walled off, then you are slightly behind, but the game is still very playable. But, if opponent doesn’t handle it well enough, or you happen to catch him/her at the worst possible time. You can win right there.

Similarly, a two barracks Reaper opening can result in all of the above possibilities.

• Build order advantage
• Build order disadvantage
• Build order win

It is definitely a good build to have in your arsenal if you plan to play in a tournament as you want to mix up your builds. This has been recently used in the Ro16 WCS Korea several times, which indicates that it is a competitive build.

INnoVation vs. Flash
– Match: WCS Korea Ro16 Group B, game 2.
– Map: DF Atlas.
– Build: INnoVation used 2 Rax Reaper, while Flash used 1 rax expand.
– Result: INnovation won right there when the number of Reapers reached the tipping point.

Bomber vs. Taeja
– Match: WCS Korea Ro16 Group C, game 1.
– Map: DF Atlas.
– Build: Bomber used 2 Rax Reaper, while Taeja used Gas before Rax into Banshee.
– Result: Bomber produced only three Reapers and transited into a standard game. But he certainly got an upper hand through the Reaper exchanges.

Taeja vs. Bomber
– Match: WCS Korea Ro16 Group C, game 2.
– Map: Akilon Wastes.
– Build: Taeja used 2 Rax Reaper, while Bomber used 15 Gas expand.
– Result: Bomber held the Reapers well, and gained an opening advantage.

Build order

10 – Supply Depot
12 – Barrack (@100% – Reaper)
12 – Refinery
14 – Barrack (@100% – Reaper)
17 – Orbital Command
17 – Supply Depot
Constant Reaper production.
@400 mineral – Command Centre

Explanation

Although the build order is rather short, you have to make a decision early on in terms of the number of Reapers you get. The optimum number ranges from three to five. If you get one or two, the second barrack is simply redundant. The value of the sixth and onward Reaper drops significantly in comparison to the fifth. This is because you should reach the tipping point at four or five. If five Reapers are not enough to win you the game right there, then the sixth one will not help. It is better to start transit into a normal game and start Marine production.

It is not meaningful to put it out in words to explain how to micro the Reapers. But there are two important things that you must do in order for this build to work effectively. First, the opponent must not know that you have a second barrack. It is impossible for you to deny your opponent the information that you are doing a Reaper opening, but you cannot let him know you have the second barrack.

Second, the timing to show your Reapers. Your first Reaper should do what a Reaper does normally – go into the main to scout. Opponent does not know if you are doing a one barrack Reaper expand, or a two barracks Reaper build. So park the second Reaper near your opponent’s natural, and do not show it to your opponent with the first. This is because the timing of the second Reaper will give away the information that you are doing a two barracks Reaper build. When the third Reaper arrives, that’s when you strike hard as it is the best Marine vs. Reaper ratio you have for the whole Reaper production time frame. It is possible to kill off all the Marines and force opponent to pull Scvs. If opponent doesn’t hold it off well enough, your subsequent Reapers can end the game.

Map choice is critical for this build. As you can see from the three samples from WCS Korea Ro16, it works well on DF Atlas, but not on Akilon Wastes. In order for this build to work well, Reapers need to have a location to jump into the main which is not close to the ramp. Akilon Wastes doesn’t fulfill this requirement.

For the current ladder season, this build works better on the following maps:

• Neo Planet S
• Star Station
• Derelict Watcher

Conclusion

2 Rax Reaper build is not a cheese, as it can transit into a standard game easily. But you gain build order advantage with good micro, or even an easy win.