TvP Innovation’s Safe Bio Build

General Overview

This Reaper FE gets out a fast Factory so that you can defend any early Protoss pressure with Widow Mines and Bunkers.  It then transitions into standard Bio play for a 10 minute Medivac attack.

Build Order

  • 10 – Supply Depot
  • 12 – Barracks
  • 12 – Refinery
  • 15 – Orbital Command
  • 15 – Reaper
    • Pull 1 SCV out of your Refinery
  • 17 – @400 Mins, start 2nd Command Center and Reactor on Barracks
  • 18 – Supply Depot
  • 22 – @100 Gas, start Factory and Bunker (at natural)
    • Put 1 SCV back into Refinery
  • @100% Factory, start Starport and 1 Widow Mine
  • @100% Starport, start Medivac, 2 more Barracks, and 2 more Refineries
  • @100% Medivac, start a Tech lab on both the Factory and the Starport and make an Engineering Bay
  • Benchmark: When your Medivac finishes (@7:20ish), you should have 1 Reaper, 1 Medivac, 1 Widow Mine, 12 Marines, and 33 SCVs.  Drop Widow Mine and Marines.
  • @100% 2/3rd Barracks, swap onto the two Tech labs and start Stimpack, Combat Shields, and +1 Attack
    • Start constant Marauder production
  • @50 Gas, start Reactor on Starport
  • @100% Reactor, start constant Medivac production
  • Push out when your first set of Medivacs finish (@10:10ish) with 3 Medivacs, around 6 Marauders and 26 Marines, and 53 SCVs at home.


The very beginning of this build is somewhat fragile (opening with a Reaper FE means that you only have 1 Reaper for quite some time), so scouting with this Reaper is absolutely crucial.  You CANNOT lose your Reaper.  Instead, use it to spot how many Assimilators your opponent has taken, when they expand (or note if they do not get a fast expansion by around the 5 minute mark), and how many early game units they are defending with.  You must keep the Reaper active on the map to spot for any early aggression and also to prevent your opponent’s first Stalker or Zealot/Stalker from getting to your base and doing damage.

If your opponent has not expanded by around the 5 minute mark, then prepare to deal with 1 base play as you sacrifice your Reaper into your opponent’s base.  If you are playing against a 1 basing Protoss, then constantly produce Widow Mines – do not just stop at 1.  Also, if you do not know whether or not your opponent has built a Stargate, building a Bunker in your main mineral line for 4 Marines to sit in and shoot any early game Oracles is not a bad idea too.


This build can only transition into Bio play, for you have committed all your resources and time into getting the Infantry upgrades and Medivacs.  After this build, get Concussive Shells, take a 3rd Command Center, continue your upgrades by getting and Armory and another Engineering Bay, build 2 more Barracks, and react to whatever midgame splash damage your opponent is getting.  Against Colossi, get a 2nd Starport; against Storm, get a Ghost Academy.


  • If you are not comfortable with pulling SCVs in and out of gas, then simply ignore the two notes telling you to pull an SCV out of and then later put one more into gas (at 15 and 22 supply).
  • Early game Stalker + Mothership Core pressure can be game ending if you lose your initial Reaper.  Do NOT lose your Reaper.
  • If you believe your opponent is playing with an aggressive 1 base build (for instance, if you scout a Stargate/proxy Pylon/lack of Nexus), then continue making Widow Mines.  Also, consider moving your natural to your main base and defending on one base.
  • Oracles massacre un-upgraded Marines, so position your Widow Mines effectively.  Also consider adding a Bunker in your mineral line if your opponent has a Stargate to further defend Oracle pressure.
  • If your opponent is not playing aggressively, then drop your Widow Mine(s) and Marines at your opponent’s base.  Do not over commit if your opponent already has a detection/Cannons ready for you.
  • This build gives you enough gas to start Marauder production much earlier than most other builds.  Be sure to ramp up your Marauder production early in order to make a beefier army than your opponent.
  • Move out as soon as your Medivacs pop.  Stimpack, while not yet done, should finish by the time you get to your opponent’s base.

Pros and Cons

This build is strong because it gives you the economy and infrastructure on par with a Wings of Liberty style 1rax FE.  Also, this build makes a fast Reaper to scout throughout the early game.  Not to mention the fact that you start Widow Mine production very early in order to stay safe against any potential Protoss aggression.

However, this build is somewhat vulnerable to early Protoss pokes, especially if you lose your Reaper.  Another problem with this build is that you start Stimpack a little later than other builds that go directly for Stimpack research, but you will still have Stimpack done for the 10 minute Medivac timing.

Favorable Maps

This build is strongest on larger maps and also maps with lots of cliffs on the main base so that a Reaper can jump up and get lots of scouting information.

  • King Sejong Station
  • Catallena
  • Foxtrot Labs
  • Nimbus


Innovation performing this build and slight variations against sOs in the 2013 Season 1 WCS Finals

Zan’s YouTube Tutorial over this build

Innovation’s Safe Bio Build Tutorial Replay vs a Very Easy AI