Chop: the right most card you would likely discard.
0-Always scud over to the right
This is done automatically on game sites like BGA. After a play, the remaining cards will be pushed to the right, and a new card will be placed leftmost in the hand. This card is “fresh” and will often be used in finesse, reverse and bluff as it is often the one every player is waiting for.
If you play the physical game, get used to do that, absolutely! It simplifies the way you play your cards. It is also an essential component of the other conventions described below for, this way, the cards fall right toward the chop where they will be saved (or not).
If you don't, you're a masochist and I respect the fact that you dream those 30 points playing like that
1-Play left. Discard right.
When given a multiple clue, always play the leftmost card! That's the one other players want you to play. After playing that first card, the second is up to your judgement. It will often be clued a second time to indicate when it becomes playable.
You can safely assume that a card recently clued to you is playable, if it's high in you hand (left) and there is at least an unclued card after it (see 6-Saves).
On the opposite, if you choose to discard always do so with the rightmost card that doesn't have any clues yet. Following “scud right” you will notice that useless cards fall right, as everybody is waiting for fresh playable cards.
The psychological effect: Discarding is the best move, not cluing!
Hanabi is a game where players have to trust each other. If nothing is said about your hand, it means you contribute nothing and it will remain like that until you draw a fresher card.
There is a recurrent beginner's mistake: cluing, cluing, cluing without ever discarding. If you trust your teammates any unclued card is just another discard waiting to happen. Discarding recycles your hand and makes the game move faster, while giving a clue token for the team to use.
If your gutt makes it hard for you to discard, think about it this way: You play others' hands for them and they reciprocate. If you discard something important, it's THEIR fault, never yours!
The discard convention.
Always assume a player will discard! Never assume s/he will use a clue token if there are some available. Sometimes the game doesn't give the players any playable cards to clue...unfortunately.
2-Finesse (3+ players).
This is a way to play two cards with only one clue. Those clue tokens are vital to the win so why not saving money!
Finesse is carried out as such: A player will give a clue, one card too far (1->3). Since players can see that there is a gap, beginners will assume a mistake, although it's not. If you trust your teammates, check other hands to see if you see the gap card (here the 2). If you don't see it, YOU have it!
Generally it will be the leftmost card, the freshest, the one everybody has been waiting for.
Or if you have a numeral clue, it could be that clued card.
3-Reverse Finesse (3+ players).
This is the same as finesse but backwards. The player with the gap card plays after the player with the card ending the sequence.
The consenquence of a reverse finesse is that the player that is hinted the clue it will have to discard or clue someone else to “pass” his/her turn.
4-Bluff (3+ players).
This strategy uses the knowledge of finesse. A player will clue a card hinting a finesse to another player. Yet, when the player that recognizes it plays, it's not the card he though he would put in play, but it fill another color as the card was technically playable.
A word of caution with bluff: Someone has just given you a bad clue for the sake of having your teammate play a good card. When it is your turn to play and the card that was hinted with a bluff turns out not to be the same color as the clue given to you, you should prevent yourself from playing it, on a reflex. You have to be aware of the clue given and played card! Following the game closely will prevent an unwanted fuse resulting from your lightheadedness.
5-1's without color clues are always playable.
In the beginning, players will often clue multiple 1's. Yet, beginners will sometimes refrain from playing the others as the “left-right” dictates the second (or third) card is up to their judgement.
To simplify and in order so save clues, players consider that all 1's are playable unless they are clued a color to reveal a mistake or a doublet.
When an already discarded card is in the chop of a player, it is customary to indicate it to him/her with a number. The player must then understand that because the card is in the chop, it's a save and it should be kept for later.
In some situations, saving a card will result in cluing a card higher in the hand. Always consider a save before playing left-right.
!!!Sometimes there will be two indentical cards in two players chops. At least one must be saved but it will look like it's a playable card because its counterpart is not yet in the discard. When clued a number on the chop always check others' hands!!!
7-The next color clue is in sequence.
If you've just noticed a reverse finesse but the sequence has not ended yet, you might be surprised that a continuation of this reverse is played on you...reversed. The gap 2 has been played but another player gives you a color clue before the end of that sequence (You are seated before the player who has the 3). You could assume that you also have the second 3 of that color and treat it as a discard (or worse, play it). But you'd be wrong. This color clue indicates you have the one following the 3 in that color (thus the 4).
Following the minimalist perception of these conventions, nobody will give you a discard clue on something that will be done so naturally.
8-Color is better than number unless...
Giving a color clue is quite straight forward. You should play that card as it often is the next in sequence. But sometimes (especially in harder versions) people will prefer giving you a number.
This number is a clue by itself! It tells you that the higher card(s) might be the same color and it was impossible to give you a color clue. Thus you can start speculating on the left part of your hand.
Strategy overall: keep it minimal.
Players should always try to clue as to never give an unneeded or useless clue. There is no reason to give four 4's to a player when it's the beginning of the game (unless you want a good laugh). Moreover, once clued, a card won't be discardable until told so (using a precious clue token).
Also it moves the chop up, clogging the hand eventually.
This is also a reason why some players don't receive any clues. We like them too, but their hand is rubbish and it should be recycled accordingly. Remember that discarding is never a bad play!
Fuses are ok if they allow to save something.
Fuses are never fun to get. A card is sent to the discard without the benefit of getting a new clue token (and it angries your teammates).
The only situation for which everybody will be happy that you'd play a fuse is when there are no other ways to clue a card that should be saved for later. Count it as a half-clue for what you play in the discard has one of the qualities (number or color) of the card that is now safe in hand.
Three fuses is plenty. To give the game a fighting chance, try playing without them (one is too many).
Strategy for opening 1's.
Since you should always assume a player will discard, giving the 1's to a player that has a 1 in his/her chop is a good way to avoid waiting for another 1. Thus this players becomes a primary cluing target if no other 1's of the same color are in hands.
End game unconventional discard
A discarded card that doesn't follow conventions can mean the place of a playable card in another player's hand if there aren't sufficent clues to indicate it.
Middle game unconventional discard
A player discarding a visibly playable card, could do so to indicates another payer s/he has the exact same card. This is a strategy to avoid keeping clued cards in hands that will serve no purpose afterwards.
Well I hope you have as much fun as all of us playing hanabi.
This game is unique. It has something of poker, counting cards, yet it's communal. It looks like child play but it requires a learning process and some analytical logic. It's fun with friends but unforgiving to people who don't follow. It's always the same until that deck decides to show you otherwise. It's sometimes frustrating, but who could be mad with so many colors. It's unexpensive, yet you know deep in your heart you would pay 50$ for it (which you can). Most of all it makes me want to trust you all, a human quality of the highest regard.
Congrats to Antoine Bauza for his simple yet powerful realization. I hope to see you around the tables