Basic tournament rules across the board. Top places get grand prize, and high consolation prize. That’s the rules of tournament. Gambling and gaming however are synonymous, and people have a hard time differentiating between them. So here you go.
Tournaments: Not gambling, but a structured system with reward. To enter a tournament in real life, or in a game, there is an entry fee.
Summoning Heros: Gambling
Hoping For Good Boards: Gambling
So no matter what you do, you can’t differentiate when a Random Number Generator is involved. And random number generators are used for everything in video games nowadays. Honestly if you think about it this game really has not many skill factors to it because your roster is based off of your luck gambling in the slot machine that is your summon window. And your raiding ability or ability to clear stages and events, is not based on your ability to turn a bad board into a good board, but your luck in getting the Cascade for a good board.
So voila, Empires and puzzles is a casino!