https://www.gamespot.com/articles/free-hearthstone-card-pack-for-starcraft-anniversa/1100-6457576/

Blizzard has kicked off its latest cross-promotional event for StarCraft's 20th anniversary, this time in Hearthstone. The digital CCG is offering three packs for winning a match in this week's Tavern Brawl, which carries a distinct StarCraft flavor.

The "Portals to Another Dimension" Brawl assembles a 10-card deck from your chosen class, then fills your deck with 20 more cards from one of three categories: Tech, Swarm, and Mind. Those portals cost one mana and summon a discount minion or spell that fits into one of those categories. Tech is filled with mechs and explosions, Swarm has toxic creatures, and Mind packs psychic powers. Each is meant to correspond to one of the classic StarCraft factions.