As Terran
Make:
Scan
Viking
Marine
VikingMarinePick off Observers before a push so Protoss loses vision and detection.
Open in the counter tool with Observer tagged ->As Protoss
Make:
Observer
Stalker
PhoenixObserver wars are vision wars. Protect yours and remove theirs.
Open in the counter tool with Observer tagged ->As Zerg
Make:
Overseer
Hydralisk
CorruptorClear Observers before burrowed or Lurker play reveals itself.
Open in the counter tool with Observer tagged ->
Zealot
Adept
Sentry
Immortal
Warp Prism
Colossus
Disruptor
High Templar
Archon