10-10 was designed for the 2019 exhibition これはトリテなのか (Is this a trick-taking game?), for games that pushed the boundary of what could be considered both a game and a trick-taking game.
The game uses a deck of 55 cards, each with a major rank and a minor rank. The major and minor ranks both follow the one 1, two 2s, three 3s... structure. However, the combinations are structured such that the 1 occurs on 2 cards (1-10 and 10-1), while the 10 occurs on 19 cards (10-10 through 10-1, and 1-10 through 10-10). The cards are suitless.
In the game, rather than the suit of the lead player's card, it is the combination of cards played by the first and second players that determines what must be followed. If the major ranks of the first 2 cards match, then subsequent players may only play a card with that major rank. If the minor ranks of the first 2 cards match, then subsequent players may only play a card with that minor rank.
However, if the first and second card share neither the same major or minor rank, then all subsequent cards can match no previously played cards' major or minor ranks.
Players earn 1 point per trick taken, and the game lasts a number of rounds equal to the players. The person with the most points at the end of the game wins.