A friend introduced me to the Korean card game Choson recently at a cosy local boardgame convention. Choson uses a deck with cards valued 1-9 with 1 card with value 1, 2 cards with value 2, and so on up to 9 cards with the value nine. Plus ten event cards for a total of 55 cards. Players compete to win control in each of the series by playing cards to win influence and to sabotage other players.
I’m a fan of the Triangular Number Sequence since my university days: 1, 3, 6, 10, 15, …, the series of the sums of all natural numbers from 1 to n. The classic anecdote is that the teacher of young math genius Gauss was annoyed that his student was so fast to solve the tasks he was given that the teacher finally asked him to calculate the sum of all the numbers from 1 to 100. Gauss realised that the numbers formed an equilateral triangle and came up with the formula n(n+1)/2 to calculate the sum of natural numbers from 1 to n.
So I was fascinated by a card game using this distribution in an otherwise standard size deck. There is also a nice juicy “saddle point”: While each card has a theoretical value of scoring you 1 point, you could potentially score 9 points by playing a single 9 at the right moment in the game. Good stuff to build a game on.
But I also felt that Choson was a little fuzzy here and there and noticed which rules were hard to learn as we played. Also, as the game is likely hard to come by (it’s a Korean game from 2014), I decided to create my own version of a card game using the numbers 1-9 with the count of each matching the number.
This game now exists. It’s called Nine Kingdoms. The print-and-play edition is available here.

Design thoughts
I playtested and iterated the design of Nine Kingdoms for one week. I ended up with a deck of 60 cards, adding 15 jokers (with the symbol $). With five cards dealt to each player each round, 60 cards works well for both 2, 3, and 4 players. You play for six rounds, shuffling discards into the deck each round only after you have been through the deck once. To track claimed kingdoms, I added 9 kingdom cards.
Each player picks two cards to play each round. Certain combinations of cards allow you to discard or steal cards from your opponent’s tableau.
Compared to Choson, Nine Kingdoms is more cutthroat. As it is easier to play a hand that discards or steals a card from the opponent, there is a lot of infighting.
It is also simpler to learn as it avoids counters; you always get five cards and pick two. Instead of counters, you collect cards in a face-down scoring pile. Plus, you get a card when you claim a kingdom that also tells you what the special power is.
There is a nice learning curve as you discover which combinations of cards to play in different situations. For instance, when you are the first player, you know how all cards on the table will look when you play, but when you are the last to play, you want to play cards that give you flexibility to decide later based on how the situation on the table has changed.

Alternate title: Six-seven
I haven’t added a theme. I’ve brainstormed everything from fluffy animals in the forest to vampires, vikings, and wizards. Maybe just keep it as a generic renaissance fight for power to signal its Machiavellian nature.
So Nine Kingdoms is a working title. I considered to call it six-seven. Not because the combination of playing a six with a seven is anything more or less special than many other combinations. But perhaps exactly for that reason. Just a nice little card game in a box right next to the candy and tobacco shelves close to the cashier. With an easy-to-remember name for all the young kids to pick up.
Don't know what happens with the game next. Now it is out there. If you try it out, let me know!