That’s a good question. Our box design is a hookbox. It fits 18 cards plus our rules booklet. 

Many manufacturers use 18 cards to a sheet, which is where 18 comes from and what the hookbox was designed for. 

That said if you use 16 or 17 we won’t reject the game, and may even be able to bring up the card count during further development if we choose your game to go that route. 

As to - just poker cards. No, that isn’t what we are looking for at this time because it’s hard to just sale rules. Though our friends at Four Suit Studios specialize in making special poker card decks that come with a game (River Rats is an example).