When you aren't getting ledgendarys in this game it's when the level is not high enough and in the high arena's.
I didn't get my first ledgendary till I was at arena 7.
When you want some ledgendarys save your gems so you can get ledgendary chests and have a fighting advantage. When there is a gem rush don't just go for the gems but remember that you are still able to lose trophies,so try to set up a deck that is equally balanced like a hog rider then throw out the goblin barrel and finally use a card that fills up the last slot to do efficient damage.the goblin barrel is so that the hog takes all the damage and the goblins do a lot of damage to the tower as the hog slowly goes down.