The co-operative fireworks game — everyone wins or nobody does
Hanab — the game widely known as Hanabi — is a co-operative card game with one brilliant inversion at its centre: you hold your hand facing outwards. Everyone can see your cards except you. Together you are trying to launch five firework displays in order, and the only way to learn what you are holding is for a teammate to spend a clue telling you.
Build five fireworks — one per colour — by playing cards 1, 2, 3, 4, 5 in order. A complete set of five fireworks is a perfect 25. There is no individual winner: the team scores one number together.
Fifty cards in five colours. Each colour has three 1s, two 2s, two 3s, two 4s and a single 5. That distribution is the whole game in miniature — 1s are cheap, and every 5 is irreplaceable. Discard a 5 and that colour can never be finished.
On your turn you do exactly one of three things.
The team shares 8 clue tokens. Giving a clue spends one; discarding returns one, and so does completing a firework by playing its 5. Run out of tokens and somebody has to discard or gamble on a play.
You have 3 fuses. Each misplayed card burns one. Burn all three and the display ends immediately with nothing to show for it.
Because a clue has to do two jobs at once. “Your second card is a 3” is a fact, but the fact that your teammate chose to spend a token on that card, right now, is usually the bigger message. Good Hanab is played in the space between what was said and why it was worth saying — and that is exactly what makes it a famously hard problem for AI as well as for people.
They are the same game. Hanabi is the published name — Japanese for "fireworks" — and Hanab is the name used here.
That is the core mechanic. Every player can see everyone else’s hand but not their own, so the only way to learn what you hold is for a teammate to spend a clue token on you.
25 — all five fireworks completed from 1 to 5. Each completed firework is worth up to five points, one for each card played in order.
Three. Each card played out of sequence burns a fuse, and burning all three ends the game immediately.