Play games
Choose the game that interests you and play itfor free.
Complete the quests
Every game has some quests for which you will receive Soul Gems.
Receive rewards
You can exchange your Soul Gems for Steam Wallet top-ups, game keys, CS:GO Skins and other rewards.
Riot Games have been throwing their 200+ years of collective game-designing experience left and right recently. It seems like every time a fan criticizes League of Legends, the developers always fire back with the same statement.