During the Dota 2 The International 2017 tournament, Valve announced Artifact, a new card title based on its popular MOBA, scheduled for 2018.
Valve reveals DOTA card game, Artifact
Artifact will present lines of attack like in the MOBA, heroes like the Bounty Hunter, and will have letters like the Barraca that will serve to push waves of minions in each attack. Basically, it will be a DOTA 2 card game.
It looks like Hearthstone will have competition. Meanwhile, we are still waiting for news on Portal 3, Team Fortress 3, Left For Dead 3 and Half-Life 3.