RogueHanafuda

RogueHanafuda is a roguelike deckbuilder built on the rules of Koi-Koi, a traditional Japanese hanafuda card game. Each turn, the player plays a card from their hand and takes the matching month from the table. Completing a yaku (a scoring combination) presents a choice: stop and bank the points, or call Koi-Koi to continue. Each Koi-Koi raises the stakes and completing another yaku multiplies the score, but if the hand runs out before another yaku is formed, everything staked that month is lost.

The scoring hands follow hanafuda conventions. Brights are limited to five cards in the 48-card deck, and there are ribbon sets (Akatan and Aotan), the boar, deer and butterfly animal set (Inoshikacho), and Hanami and Tsukimi, which pair the sake cup with the cherry blossom or the full moon. Animals, Ribbons and Junk are completed by count alone, with each additional card increasing the score. The run is structured around rent: a bill comes due every month and is paid with the points scored during that month. Any shortfall carries over, missing one month grants a grace period, and missing two in a row results in eviction. Rent increases over the year, and surviving the twelfth collection wins the run.

Between months, a shop allows players to spend gold on relics, open hanafuda packs and remove unwanted cards from their deck. Relics can strengthen a suit, multiply the score or change the rules. Additional yaku can be unlocked, including Godori, Chodan and four month sets (Iris, Maple, Rain and Paulownia), which are not part of the base rules, and existing yaku can be levelled up to increase their value. The game includes more than 20 relics and six unlockable yaku, with the shop varying between runs. A full twelve-month run takes around 30 minutes.