What follows is a revision of the Decktet Game Idea I posted last week, after a playtest showed some flaws with the original idea. Changes are in boldface.
So, I had an idea for a game using the Decktet. Seeing as most of the cards have multiple suits, the following might work.
The game would be a "tree-building" game, which much like tableau builders, would involve players taking turns building piles of cards. The difference between a tableau builder and a tree-builder, is that the trees grow into multiple piles over time.
So, to start the game, take the extended Decktet, and take out the six Aces. Shuffle those and place them face down in the center of the table. These are your "root" cards. Turn the top two over, and move them to spacious areas of the table. These are the starter trees.
Shuffle the rest of the deck together, and deal 5 cards to each player to form the hand.
Gameplay is in turns, each turn a player either draws a card from the draw pile, plays a card building on a tree, harvests a tree, or unroots a tree. Regardless of what they do, they draw an additional card at the end of the turn. There is no maximum hand size.
Drawing a card eats up your action for your turn. However, since you draw a card at the end of each turn, you effectively draw two cards this turn.
Playing a card on a tree involves playing a card which shares a suit and a higher rank than the card that you are playing on. All cards aside from Crowns may be played off of, and all aside from Pawns and Courts may have two cards played off of them. Pawns and Courts may have three cards played off of them. For the purposes of this game, Pawns and Courts are of any rank, even half ranks, such that they may be played in between two cards of any rank that they share a suit with. Crowns may not have any cards played off of them, and as such form ends of branches. The Excuse counts as any rank of a single suit, chosen by the player who played it.
Harvesting a tree is how you score points. A player scores points for the number of Crowns in a tree they harvest. A tree with zero Crowns may not be harvested. When they harvest a tree, they collect the Ace and place it in front of them, then return the rest of the cards to the discard pile. When harvesting future trees, they gain bonus points if Crowns in those trees share suits with any aces they own. To harvest a tree, that player must discard at least one of each suit from their hand that matches the crowns in the tree. Alternative scoring: Players score points for the longest branch in the tree, and additional points for crowns matching their owned aces.
If a player cannot play a card, nor can they harvest a tree, they must unroot a tree. Additionally, unrooting cannot be a voluntary action. Unrooting a tree involves shuffling that tree's Ace into the root pile, returning all other cards to the discard pile, and starting a new tree (see below).
Starting a new tree is done by shuffling the root pile and flipping the top card over to form a new root. This is not an action and does not take a turn. It is mandatory whenever there are less than two trees in play, and the root pile is not yet exhausted.
When a player must draw and there are no cards to draw, the discard pile is reshuffled to form a new draw pile.
The game is over when all six roots have been harvested. The player with the most points wins.