Hanabi is a cooperative card game where you can see everyone's cards but not your own. The deck consists of 50 cards in 5 colors; each color has three 1s, two 2s, two 3s, two 4s, and one 5. The goal is to build up five stacks of each color from 1 through 5, like in solitaire. The team starts with 8 clues(see2c below).
You have three options for each turn:
Play a card: A player can pick a card from their hand and attempt to play it. If it's the next card for any of the five colors, it gets played onto that pile.(You don’t need to know which pile.) Otherwise, the team gets a strike, and 3 strikes ends the game.
One footnote: Successfully playing a 5 gives the team an additional clue.
Discard a card: A player can pick a card from their hand and discard it. The card goes to the discard pile and the team regains an additional clue.
Spend a clue: A player can spend a clue to give information to another player. They choose a player and either a number or a color, and then tell which subset of their cards matches the clue. The subset must be nonempty.
Assuming the team does not strike out, the game ends after the last card is drawn and every player takes one more turn. Your score(out of 25) is the number of cards played successfully.
The H-Group conventions
When playing on hanab.live, most players follow a fairly explicit set of conventions so that clues have unambiguous meanings(at least early on). To learn these conventions properly, you will have to read the Beginner’s Guide, and later on the Learning Path and the Reference.
When you’re first starting, here are the specific principles that I think make sense to learn first. There’s a YouTube video with roughly the same information as below. You can also see the below picture for quick reference of the five“axioms”.
0. Play left, discard right(chop)
When discarding, discard your rightmost unclued card. This card is called the“chop” card, for“chopping block”.(We use this convention because this will be the oldest card, as cards are drawn on the left.)
1. Clue Focus
When a clue is given, the clue is always focused on one card, as follows:
If the clue touches the chop card, the focus is ALWAYS on the chop card.
Otherwise, it is on the leftmost new card(card not previously touched).
2. Good Touch Principle
The touched non-focused cardspromised to be eventually usable but not necessarily right now.
Corollary: you should NOT touch the same card twice, i.e. do not touch two red 1’s.(If a teammate has duplicated cards, one strategy is to just wait for one copy to discard.)
3. Play vs Save(for focused card)
The focused card is promised as either aplay clue or a save clue.
A play clue is a promise that the focused card is playable“now”: i.e. that all the connecting cards are ready to be played.
A save clue tells you to not discard the focused card because it is important. There are strict requirements on what you may save:
You can only save cards on chop.
The following saves are allowed:
5 save: You can(and must) save a 5; if you do, you must use number 5(not color).
There is one exception: before the first discard, you may save a 5 even if it is not on chop, but you must do so with number 5. This is called a 5 Stall.But you should only do this if there are no“normal” clues to give.
2 save: You can(and must) save a 2 if you cannot see the other copy of the 2 of the same color. You must use number 2(not color).
Critical card: You can(and must) save any cards for which the other copy is discarded. You may use either number or color.
In principle, sometimes it will not be clear whether a clue is play or save, and if so you should wait for further information. However, in practice, because the conditions on the save clue are so constrained, you can often rule out“save clue”, in which case it must be a play clue.
Remember that a play clue is a promise that the focused card is playable now. So what if you see a play clue given where a connecting card is missing? For example, let’s say a red 2 is play-clued, but no red cards have been played yet.
The answer is that if you don’t see the connecting card, it means you have it.
If you have any clued cards that could fit, you should play them from left to right.(This is called a Prompt.)
If you don’t have any clued cards that could fit, you should play your leftmost unclued card.(This is called a Finesse.)
Abridged rules of the game (adapted from here)
The H-Group conventions
0. Play left, discard right (chop)
1. Clue Focus
2. Good Touch Principle
3. Play vs Save (for focused card)
4. Prompts and finesses (aka trust your team)