Clash Royale is a game that has become very popular in both Asia and Europe. It's a combination between a tower-defence / lane pushing game and a card game. The game is played on mobile devices and is available on iOS and Android.
The basics of the game consist of collecting and levelling up cards, both spells and creatures/troops. Before starting a game you build your deck of these cards. CR is played in real-time and you deploy troops on two different lanes to push the enemy towers. Spells can be cast all over the map. These cards cost mana to play which refreshes over time. Overall the game got some serious and deep mechanics which makes it a good eSport for mobile players.
Clash Royale has gained additional legitimacy since ESL and Redbull got involved in the eSport.