Legendary limitation or improvement of the matchmaking system
I have an idea for improving the balance in the game.
I experience a battle where my opponent have 4 legendary cards and I don't have any legendary card at all.
answer 1 : create a limitation rule of 1 or 2 legendary cards per deck
answer 2 : improving the matchmaking system in order to avoid that kind of situations (0 legendary card VS at least 4 legendary cards), by create a rule which for exemple prevent to create a battle with someone who use more than 2 legendary cards than yourself in his deck.
answer 3: add a parameter which compare the strength of a deck in the matchmaking system.
For instance, a legendary card will be 4 points, an epic one is 3 points, a rare one is 2 points, a common one is 1 point and you can compare the sum of your deck with your opponent deck and if the difference is too important, then they can't fight each other.
Those answers are example, I think it exists a lot of way to fix that kind of problem.