Starcraft 2: Nigh Unstoppable 7-Roach Rush Build Order
This is a fairly fascinating build order in a number of respects. From a Starcraft perspective: it is incredibly strong. To be clear, I am certain virtually anyone who practiced this build and went onto the ladder and used it in every game would very easily rise to diamond level (currently the highest league). The seven roaches at that time in the game will destroy all but the most well-executed counter-builds.
- 10 extractor-trick to 11
- 11 overlord
- 11 spawning pool
- 15 extractor
- 16 queen (stop drones here)
- 18 overlord
- 18 roach warren
- 17 overlord (yes, two)
- spawn-larva on queen when she pops
- roach x7
As far as I know, this build isn’t too well known. There is a similar build that’s been well known called the 5-roach-rush (the 5-roach-rush comes later, and is a bit more economical). When comparing the two, the 5RR has certain situational advantages, but the 7RR build, above, has two staggeringly obvious advantages: 1) you get two more roaches, 2) you get them almost 45 seconds sooner. I’m not 100% certain this build was “discovered” by the program, but I do know it’s not been extremely popular or considered standard play so my guess is that it’s not been studied in too much detail.
The most interesting part of this build, however, is how counter-intuitive it is. It violates several well-known (and well-adhered-to) heuristics used by Starcraft players when creating builds. Some of this may be lost on you non-starcraft players, but I’ll do my best to explain.
The extractor trick is using a drone to build an extractor (remember this removes the drone), then build a replacement drone, then cancel the extractor, giving you the original drone back — this allows you to build one more worker than your supply would allow. The extractor trick, as used above, has been tested and seen to be economically inferior to a more standard play of buying an overlord on 9 supply. The extractor trick + very early spawning pool do some economic damage and induce a small larva delay, so they are almost never seen. In this case, however, the extractor trick + early pool end up speeding up the entire tech path (this is the primary reason why the 7RR produces roaches much sooner than the 5RR).
Double Overlord at 18/17
First, a quick discussion about supply. Each unit you create costs supply. So long as you have supply, you can make units. Most RTS games have a similar concept. Overlords, for the zerg, are the unit that provides this supply. So for zerg, you have to spend 100 minerals to unlock additional supply. In general, it is considered “optimal” for you to have just enough supply to not be supply-blocked. It’s generally considered wasteful to buy supply when you don’t need it (since you could spend that money, instead, on units or workers now, and buy the supply later, when you need it).
In almost all cases, it would be extremely wasteful to purchase supply twice in a row. I’m not sure any starcraft player would look at such a build and consider that a good idea. In this case though, it ends up working out so perfectly that you’d actually have to try it any other way to understand how and why. Because your desired goal is 7 roaches, you will need to construct 2 more overlords at some point, but doing them both so early is certainly surprising. During that particular period of the build (around 18 supply), you end up waiting for your roach warren to finish so you can begin creating roaches. This causes you to max out on larva, stopping regeneration. By moving the second overlord so far up into the build, this larva ends up being “free” — you’d lose it anyway because the regeneration would stop. So the only penalty to making the second overlord early is minerals, and during this portion of the build, you are not mineral-bound. The net result is that moving that overlord so far up into the build costs nothing and frees up larva regeneration to produce quicker roaches.
As for the 7-roach-rush, I’m certain if you are playing starcraft2, you’ll see this build quite a bit. As for whatever hidden and game-breaking builds remain undiscovered, that remains to be seen.
Here’s a video guide, showing the 7-Roach Rush