Castle Builder is a card drafting game where the cards you select build a castle that will house Nobles, Knights, Servants, Princesses and even a King and Queen! There are 3 rounds of drafting where the cards get more valuable, but more expensive and your gold is dwindling. Fortunately each card you add to your castle has 3 attributes, Victory Points for winning, Defense to protect against other players attacks and Favor. Favor is added to your Victory Points at the end of the game, but in between rounds it can be traded in for more gold so you can afford the more expensive cards, but then gold is not worth any Victory Points. There are other ways to gain gold such as sending your knights on adventures or buying Vaults for the Nobles to store their wealth in.
Speaking of Nobles and Knights these can be added to your castle through adding specific cards and score addition points at the end of the game. The real prize is when you add the right rooms to gain the King or Queen!
However, your opponents will be attempting to ruin your prospects of success. They can pay to discard cards you need, throw waste into your castle preventing people from inhabiting it or just outright attacking you to steal Victory Points.
It is up to you to manage your gold, Nobles, Knights and Servants to build the most impressive castle and win the game!