Can be unlocked for free by earning 10 "First Wins of the Day" in Unranked or Versus AI.
Unranked and Custom multiplayer modes are free, including all units from all expansions. StarCraft II Heart of the Swarm Free Download
Raynor, Kerrigan, and Artanis are fully free; others are free up to level 5. Heart of the Swarm Access StarCraft II: Heart of the Swarm Can be unlocked for free by earning 10
The Heart of the Swarm campaign is for everyone. While StarCraft II became free-to-play in 2017, only certain portions of the game are available at no cost. What is Free? and Artanis are fully free
The entire first campaign (Terran) is free for everyone.