From Mensa meetups to Finesse.cards: a home for Hanabi scenarios
By Marcos Montero on March 29, 2026
How a chance encounter with Hanabi at a Mensa gathering in Seville led to a mobile game experiment, a stalled AI-bot project, a summer of theory—and finally a web community for scenarios, threads, and shareable plays.
In December 2025, at RAM de Sevilla—the annual Mensa gathering in Seville—I played Hanabi for the first time. I was hooked immediately. I started reading about lines, conventions, and how strong players think in incomplete information. I liked it so much that I looked for a mobile app to practice on the go.
There wasn’t one that matched what I wanted.
There were websites, but they felt dated. What I had in mind was closer to Hanabi Deluxe: a clear, modern presentation—and ideally something that worked well as a phone app so I could play and study without friction. So I started building.
When the bot became the bottleneck
A Hanabi client is one thing; a good bot is another. I tried to structure opponents as decision trees, but the state space explodes. Every situation depends on subtle context: what was clued, what was discarded, what seat you are, what conventions the table assumes. Encoding that as a tree is an ambitious exercise: you need to know Hanabi deeply, not only to code well.
Progress on the “full” vision slowed—not because the UI was wrong, but because AI that plays credibly in Hanabi is a research project on its own.
Hanabi University and the wider world of theory
In March, I attended Hanabi University—the yearly meetup of Hanabi players from Mensa España. There I saw even more lines, table cultures, and variants. I dug into powder and multicolor extensions and kept reading online.
That led me to H-Group, a community of a few hundred people dedicated to Hanabi theory—what they call conventions. I use the word cautiously myself: not everything labeled a “convention” in the wild matches how I think about agreements at the table, but the depth of analysis there is undeniable. They organize on Discord and play on Hanabi Live. The ecosystem works.
Still, two gaps kept bothering me.
First, visual experience: many flows still feel tied to older Board Game Arena–style layouts. They are usable; they are not the same sensation as sitting at a Hanabi Deluxe–style board.
Second, conversation shape: a Discord server is great for voice and quick chat, but it is not ideal when you want long-form threads—to post a position, ask “what would you clue here?”, branch replies, or collect exercises like on a forum or Reddit.
Why Finesse.cards
I already had app-oriented work in motion for a Hanabi-like experience. The idea crystallized: use that same stack mindset to ship a web focused on recreating scenarios from the table and hosting threaded discussion around them—plays you can link and share like any other community content.
That is finesse.cards.
Today it is fully usable: Google sign-in, posts for exercises and questions, shareable pages for social networks, support for powder and multicolor, and tables for two through five players.
It is not a replacement for Hanabi Live or for H-Group’s theory work. It is a different layer: a place to show a position, argue lines, and archive scenarios in a format the open web understands.
If you play Hanabi—or you are curious after reading this—take a look. The story started at a Mensa table in Seville; the tool is my answer to “where do we discuss this move next week?”