These cards are more powerful than your starting cards and vary in cost and strength and are, usually, purchased into your discard pile.
There is a common pool of cards available for each player to purchase.The discard pile is shuffled when the draw pile is empty. Decks are shuffled and a starting hand is drawn (almost always five cards).Starting hands of a set number of cards (frequently 10), containing a predefined number of cards which either help you purchase new cards or help you towards the ultimate game goal (which can be scoring points, defeating an opponent, etc…).Many people instantly associate deck builders with Dominion, so this is as good of place as any to start. Some very basic mechanics found in Dominion have been repeated many times over. Dominion set the groundwork of what we will call a “classic” deck builder.
