Terran Opener (TvT) 1rax Three Reaper Harass Expand

This build is really effective most of the time, usually scoring yourself a small worker count lead and useful scouting information, and is easy to simply transition into your favored follow-up, be it bio or standard bio-mech.

Here is the build order:

10 Depot
12 Barracks
13 Refinery
15 Orbital Command
15 Marine
@100% Marine, tech lab
Command Center while tech lab is building
Pump three reapers, scout and clear watch towers with first reaper



After using your three reapers, you can simply throw down 2 more barracks to execute a bio expand or a factory followed by starport, and possibly extra barracks. This build allows you to see what your enemy is doing and react. Bio Expand is usually a safe follow-up.

This build is very weak vs. Banshee openers, so be sure to scout for the banshees so you can react with engi bay and missle turrets.

Good luck, and good tvt'ing.