Score the rank of Silver in the “Covert Ops” challenge mission.
Destroy 15 Infested structures at nighttime in the “Outbreak” mission on Hard difficulty.
Attack for 20 seconds with no counterattacks in an Unranked or Ranked game.
Score the rank of Bronze in the “Tactical Command” challenge mission.
Destroy 4 Command Centers, Hatcheries, or Nexuses in an Unranked or Ranked game.