TvZ 3rax Stim Timing

General Overview

This 3rax Stim Timing gets a lot of Bio to attack your opponent before they have set up their midgame.  It also opens with a Reaper for some early game scouting.

Build Order

  • 10 – Supply Depot
  • 12 – Barracks
  • 12 – Refinery
  • 15 – Orbital Command
  • 15 – Reaper
  • 16 – 2nd Barracks
  • 17 – Supply Depot
  • @100% Reaper, start Tech lab and 3rd Barracks
  • @100% Tech lab, start Stimpack Research
  • @50 Gas, start Reactor on 2nd Barracks
    • Constant Marine production
  • @100% 3rd Barracks, start Tech lab on 3rd Barracks and Combat Shields
    • Continue Marine production out of 2 Barracks, Marauders out of 1 Barracks
  • Attack your opponent when Stimpack and Combat Shields have finished (@7:20ish) with around 17 Marines, 3 Marauders, and a Reaper.


This 3rax opens with a Reaper for early game scouting, so you do not need to SCV scout if you do not want to.  Use your Reapers to confirm your opponent has opened with a Hatchery First build and if possible jump into the main and spot your opponent’s Extractor timing.  Knowing whether or not your opponent is getting Zergling Speed tells you with what units they will be defending the attack with.

With your 3rax Stim Timing attack, also be sure to note what unit composition your opponent is defending with.  Reinforce with Marines if your opponent has a heavy Zergling count or Marauders if your opponent has Roaches.


This is a strong 1 base attack that gives you Stimpack and a lot of Bio, so your follow-up will be very slow.  That being said, you should start to float some minerals as you are reaching your opponent’s base, so building a 2nd Command Center, getting Combat Shields, and starting a Factory to tech towards Medivacs and standard Marine/Marauder/Medivac/Mine play is the best choice.

Pros and Cons

This build is a strong 1 base attack that can crush your opponent early before they have their midgame even established.

However, this 3rax Stim Timing can be held with mass Speedling if your opponent scouts it coming and prepares adequately.  It also is much less economical than a macro opener such as a CC First or Reaper FE.

Favorable Maps

This build is best on smaller maps so that your attack can hit your opponent as soon as possible.

  • Overgrowth
  • Catallena
  • King Sejong Station


3rax Stim Timing Tutorial Replay vs a Very Easy AI