The second to last line answers your question.
Each day, we run 2 tournament where you can win Clintz and Credits.
In order to participate, you simply have to play during a tournament period.
The tournament ranking is accessible directly in the game : "Ranking and Tournament" then "Tournament in progress". Tournament ranking is based on the battle points won during the tournament. The Clintz jackpot starts at 1000 Clintz and grow after each battle (we multiply the Clintz earn at each battle by 2 and we put them add them to the Jackpot).
The first tournament starts at 18h30 and ends at 20h (Paris, GMT 1), the second one starts at 22h30 and ends at 0h (Paris, GMT 1).
The winner of the tournament gets 25% of the jackpot, the second one gets 15%, the third one gets 10%, the rest is split equally among each remaining players.
The first half of the players also gets a free credit
Don't worry, after each tournament, you'll receive automatically a summary of your winnings."