As Terran
Make:
Marine
Viking
ReaperDeny early Overlord vision so Zerg has to scout the hard way.
Open in the counter tool with Overlord tagged ->As Protoss
Make:
Stalker
Phoenix
AdeptRemove scouting Overlords before tech choices become obvious.
Open in the counter tool with Overlord tagged ->As Zerg
Make:
Queen
Zergling
OverseerTrack Overlord paths to infer whether the opponent is scouting or hiding tech.
Open in the counter tool with Overlord tagged ->
Baneling
Roach
Ravager
Hydralisk
Lurker
Mutalisk
Corruptor