Just a few hours ago, out of nowhere, Riot just announced their own card game called Legends of Runeterra. The game isn't open for everyone to play at the moment, but you can pre-register on Google Play to play the game as soon as possible. There are also a lot of Legends of Runeterra streams on both Twitch and YouTube now, you can go and check it out.
The game is based on the world of LoL, Runeterra. Players can create their own deck out of their favorite champions from the regions of Runeterra, each with their own unique strategic advantage.
Here is a quick rundown of basic rules in the game. Each turn, players are either on offense or defense indicated by the sword and shield on their board. While only one player can attack each round, both players can play cards. You and your opponent will alternately play a card every turn, so be careful. Playing cards will cost you mana, and your mana will be replenished every turn.
It is not very surprising that Riot will eventually have a card game. They are even planning to make a new FPS game and a fighting game too.
Legends of Runeterra will be fully released in 2020 for both PC and mobile and will be cross-platform. The game will be free-to-play and allow players to get cards by grinding in the game. Looks like Riot has learned a thing or two from the previous failure of Valve's card game.