Pocket Knights: How to get rare hero cards and rare gear cards

WP - "Pocket Knights is a new card collection game that has plenty of RPG elements to keep the action fresh. One thing that hasn't changed from past card battling games, though, is that you have common cards and rare cards that you can collect. Three, four, five, and six star cards are far more rare but far more powerful than the one and two star cards, and this goes for both hero cards and gear cards.