This document is intended to be a community effort for documenting all conventions used when playing Referential Sieve. Conventions are divided into four categories:
This document is editable to anybody with a hanabi.wiki account. Please feel free to improve the descriptions of existing conventions, add your own Experimental Conventions, or suggest changes to the documentation approach entirely! When adding/changing conventions, please also post a message in the #referential-sieve channel on the Hanabi Central Discord server afterwards so people can be aware of it and if necessary discuss the change.
This section contains the same conventions as Intro to Referential Sieve. One of the goals of that document is to be short and sweet, so the explanations here might have more redundancy for the sake of clarity.
You're only allowed to discard your chop if you have no alternative safe actions. Every time you draw a new card, your chop is reset to leftmost, even if you have previously received a Referential Discard Clue.
When a Referential Play Clue touches multiple cards, how do I know what card to play? And how can I indicate that someone's rightmost card is playable?
See Focus and Target for an alternative explanation of referential clues.
For example, if slot #1 is on chop, and slot #2 has already been clued,
When a Referential Discard Clue touches multiple cards, how do I know what card is on chop? And how can I tell someone not to discard anything at all?
See Focus and Target for an alternative explanation of referential clues.
Explaining referential clues another way:
For Referential Play Clues:
For Referential Discard Clues:
A clue that only touches already-clued cards is called a Reclue. Clues that reveal that an already clued card is immediately playable or trash give a safe action and thus should not be treated as a Referential Clue. But what if a reclue doesn't reveal any safe action?
Then, it indicates a potentially delayed play on one of the cards that it touches. Specifically, the clue is either
A player who already has a safe action (known play or known trash) is referred to as Loaded.
Referential Discard Clues cannot be given to Loaded players, because their chop would just reset to leftmost anyway after they took their safe action. Therefore, number clues given to Loaded players must mean something different.
A number clue given to a Loaded player means to play the leftmost newly touched card. This is referred to as a Loaded Play Clue.
When a player has multiple cards with the same positive clue, each of which is known to be either trash or immediately playable, they are expected to:
If not, it is a Chop Move if you are using expert conventions, see Trash Order Save.
If not, it calls for a priority play if you agreed on it, see Priority.
Thus, 1s are played left to right at the beginning of the game. If not, see 1s order Save.
Note that if cards are not exactly known playable and you could bomb a useful card, you play from right to left (Prompts, Anxiety, Priority) as older cards always have more info.
(Pink): Rank-clued cards are played right-to-left in pink.
It makes it as likely as possible that we can get a single card to play because rank-clued cards can be unplayable pink cards.
If it's on the left side, we can give a color clue, and if it's on the right, we can give a rank clue.
When the team goes to 0 clues, it enters a Zero Clue State. During a Zero Clue State, all discards must come from cards that were in hands when the state was first entered. In order to exit the Zero Clue State, a player must take an action while there is 1 clue token.
If a player discards a card when they could have played it instead, it means that another player has it in the rightmost possible position. (If the card was useful but not immediately playable, it does not promise position.)
x x [p] x
, and he does not see a p2 in anyone else's hand. He plays slot 3, because slot 4 cannot be purple, since it must have been held when the purple clue was given to slot 3!When all of a player's cards are saved and the player does not have a known play, the player is referred to as Locked.
When a player has 8 clues or has a Locked Hand, they must give a clue. Giving an obligatory clue is referred to as "stalling", and these situations are referred to as "stalling situations".
In stalling situations, referential play clues or discard clues are interpreted as normal (including Playful Positionals).
If there is no good play or discard clue to be given, then:
As a last resort:
Note that if a Hard Burn is given when a better stall clue was available, it is treated as a Play Clue (often a finesse or bluff).
When a player receives a referential clue which also identifies a touched card as exactly playable (either by good touch or by filling in a card as playable), then they are expected to play that card first and complete the blind play after.
Note that this allows for Reverse Finesses/Prompts.
When the team allows a useful card to be discarded, and you don't see it in anyone else's hand, you can suspect that you hold the other copy. You can be certain that you hold the other copy if
When a player is Finessed for a card, if they have elimination for that card, they should play the rightmost possible position for that card as a Prompt.
When known trash is clued with number, it means to play the card to the left, just like with color. It does not make sense as a Referential Discard Clue, because cluing number on the card to the left as a Referential Discard Clue is more efficient.
(Null): Trash clues with number can be Direct Discard Clues, simply indicating to discard the touched cards.
When a bad number clue is given and an intervening player sees that a play clue could have been given instead, they react by blind-playing a card that signals to the clue receiver which slot to play.
The general process is as follows:
If Bob has an unknown clued card, and Alice's clue would be reasonable if Cathy's playable was a duplicate of it, Bob should not react.
If Bob sees that the Playful Positional given to Donald could be on Cathy, they should let Cathy play into it.
In 5 player games however, the Playful Positional is always on the next player without a safe action.
Those moves can only be done in Bluff Seat.
When a 2-away card is pushed, it cannot be a double finesse, because Cathy will always assume immediately playable over a reverse finesse, so she will bomb before Bob has a chance to play the second card. Instead, this signals an Ejection.
The team should now treat the pushed card as clued. (Add a [clued]
note to the card to make it appear as clued).
Here is a table to let you know what should happen with a hand of 5 cards :
Target | Name | Finesse Position | Slot if unclued |
---|---|---|---|
1-away | Finesse | 1st | 1 |
2-away | Ejection | 2nd | 5 |
Known Trash | Discharge | 3rd | 4 |
3-away | Charm | 4th | 3 |
4-away | Blast | 5th | 2 |
With only 4 cards: 3-away and 4-away both cause a Charm (slot #2 if unclued).
When a direct play clue is given with number touching only chop, it promises that the unclued card to the right is trash. Otherwise, a color clue must be given.
(White/Null): The card to the right is known to be either White/Null or trash.
We use the same logic as H-Group for priority. See H-group Priority.
If a trash push is available and a color clue which bad touches is given instead, Bob must play his First Finesse Position to tell the receiver of the clue that the Focus of the color clue is trash. At first it will look like a Finesse has occured, but after the pushed card plays, it will become clear that the only reason Bob played was because the Focus of the color clue was trash.
Here 2 is available as a trash push (r2 is globally known) but purple is given (p4 and p5 were already gotten) thus Bob blind plays his finesse position. This confirms to Cathy that their purple 2 is trash.
She then can play #2 or discard #3
When Alice has free choice between a Color Push and a Trash Push to get a card to play, a rank clue always triggers a play from Bob's First Finesse Position.
Here Alice could clue y or 2. Both give known trash info to Cathy. Alice chose 2 over yellow meaning she wants to trigger a Free Choice Ignition.
1s are supposed to play from left to right. If a 1 plays out of order, this Chop Moves the next player without a safe action, and they cannot discard on their next turn.
In a 5 player game
Alice has 3 playables 1s on #1 #3 #4
Bob is busy :
Pink: 1s need to be played in order.
(Always on next player)
The expected discard order of clued trash is right-to-left.
If trash other than the rightmost is discarded, the next player should save some cards on their chop. The specific number of cards is determined by which trash card is discarded. This skips over loaded players, since all their cards are saved anyway.
If all players are loaded, this indicates a trash card on the next player's hand. (Imagine Chop Moving the next player in the future.)
Alice has four known trash. Everyone is loaded :
On the first turn in 2p, clues work as normal, with one exception: Number clues touching rightmost are treated as Starting Hand Stalls. When Alice gives a Starting Hand Stall to Bob, Bob must give a clue on the next turn. After Bob clues, his next discard will be his leftmost unclued card, unless Alice gives a second clue. If Bob's clue touches Alice's rightmost card, it is also treated as a Starting Hand Stall.
Brown: A brown clue touching rightmost is also considered a Starting Hand Stall.
Null: Starting hand stalls with a null-card in slot 5 are impossible. In the rare scenario no legal clue is available, you could use a t1 bomb.
If a clue is given that gives no new positive information (i.e. touches only already clued cards and does not fill any of them in), it signals a double bluff (a blind-play from slot 1 and a blind-play from slot 2).
This applies even if the reclued card could be playable; players are expected to fill in clued cards to get them to play.
Null: if slot 1 is a null card, do not continue.
When your partner is locked, and pace is >2, it is always better to discard known trash than to play a card that does not immediately unlock your partner. Therefore, if you play a card that looks like it might unlock your partner instead of discarding known trash, you promise that the connecting card is in the oldest possible position in your partner’s hand. If there’s no possible connecting card, you simply communicate that the oldest possibly playable card is indeed playable.
Following from unlock promise, it is important that a locked player is cluing playable cards such that they are fully-known. Therefore, we use a different stalling convention for locked players in 2p.
Specifically, we play with color stalls:
Null/Brown/White: With white/null a color reclue touching the leftmost previously-color-touched card is a play of a white/null card. In brown/null, rank reclues touching the leftmost previously-rank-touched card are a save of a brown/null card.
Attempting to play a card that you have permission to discard tells your partner that they are locked. Players should prefer to use this method when possible, so if you choose to use a clue to communicate a lock when you could’ve safely bombed to do so, you usually imply that you expect your partner to make a sacrificial discard. Note that sometimes you do not have permission to discard any card.
Copied from the main sieve doc.
A more contextual zero clue convention. See the main sieve doc for more details.
Suppose it is Alice's turn, and it is not common knowledge that Bob has any safe actions. If Alice then takes an action which does not (up to common knowledge) give Bob a safe action, Bob's chop is said to have "permission to discard" (or PTD). If Bob's chop has PTD, and Alice gives him a play, then the play will usually happen first. Later, when it is time for Bob to discard, he will still discard the card with PTD, regardless of whether it is the leftmost untouched card in his hand. This is because a card that has had PTD is, on average, a better discard than a newly drawn card. If Bob's PTD card is not actually trash and is about to be discarded, Alice can still save it by giving a discard clue.
x p5 x x x
x [r5] x x x
r4 p5 x x x
Or alternatively, if Bob's chop actually was useful
x [4] x x x
r4 p5 x x x
x [r5] x x x
r4 p5 x x x
x [r5] y3 y3 x
There's this concept of "cooperation" with sieve-style saves (clues that save all cards further in one direction than the introduced card most in that direction); it sometimes takes two clues to save an entire hand, so we can choose a conventional sequence of clues such that following or deviating from that sequence distinguishes between a) Alice inviting Bob to save Cathy and b) Alice putting on Cathy's chop another copy of one of Bob's cards.
A cooperation clue must follow this priority list; otherwise, it will be confused with a different-hand-dupe signal.
The reason that 2 clues are required to lock is that there is a card with the same rank as rightmost, so cluing the rightmost card reveals to the receiver the possible intent of a cooperation clue. That revelation could be important to Cathy when Bob declines to lock her because the card now on her chop is duped in Alice's hand.
If a pushed card is known not playable by context, you slide to the next playable card to the left.
What should Cathy do here ?
Of course the red clue is a push on the slot 3.
But Cathy thinks for a second what card could it be ? The only possibility is u2 but she has been holding this card since the beginning of the game and noone has clued it, so why now ?
Either she drew something valuable and the team want it to be sieved, either it's a focus slide and she is expected to play slot 1 also signaling slot 3 is a null card.
In fact when she rewinds the game she sees that the team made her discard a card to save a 5 instead of making the card in slot 3 play.
Enough thinking Cathy has sufficient info to know she should play slot 1.
U2 succesfully plays Sunday, bloddy Sunday
Duping is not so bad in ref sieve but we try to avoid it if possible.
So when you have a clued card that could match a card in someone else's hand, it's not your job to make it play or to save it. The rest of the team should be aware of what their teammates know about their hands and act in consequence.
Don't save/play clue a card a player can see on the chop of one of the next player because they will try to save/play clue it themselves.
This rule does not apply to direct play clue as the player who recieves it is then following duping avoidance strategy
If a person holds a card that have matching information for a card they call to blind play into a finesse, the called card must be exactly in finesse position.
So if Alice holds a 3 and try to finesse blue 3 by cluing blue 4 in Cathy's hand. Blue 3 must be in Bob's first finesse position (unlayered)
Layered finesses are hard to give and need extra care. The person who recieves the clue must be promised a safe action if they have to wait
When a finesse is given for an elimed card the blind play should occur from the rightmost matching card.
Bluffs are tricky with referential play clues so there are only 3 types of bluff that we allow :
There is still some debate if these types of situation should call for blind plays until the promised card is played as a layered finesse. What is sure is that a first blind play has to happen !
Those bluffs can only be given in Bluff Seat
To be discussed : after a fix do we play leftmost or rightmost ?
Due to Good touch play order : When a rank direct play clue does not identify all the card as not pink we play them right to left, e.g. 1s in the beginning.
Rank Tempo Clue :
When a rank tempo clue is given on globally known pink cards there are 2 options :
Double-Edged Pink Clue :
If Alice misranks a globally known playable pink card in Cathy's hand, it is a signal for Bob to play this slot, Cathy can then play their pink card.
It's is possible to perform a double-edged pink clue on a non globally known pink card as long as a Playful Positional Interpretation is not possible (e.g. when there is no previously unclued card in Cathy's hand.)
Fix clue on a misranked dark pink :
The basic fix clue on a misranked pink is a pink clue, e.g. Multiple ones have been clued in the first round. A pink clue on a 1 that is going to play (rightmost in pink, remember) means that this card is not a 1.
A different rank clue conveys a fix and a referential discard clue, a reclue or a loaded play clue.
This convention is maybe not working for normal pink as there are more pink cards. To be discussed.
Rank direct play clue play right to left.
Omni tempo clues are positional (colour signals the slot like Mud Clues, rank signals the slot)
When it's on Bob it's always a direct play clue.
When it's on Cathy
Bob just recieved this 3 clue. Initially this would indicate he holds o1 in slot 3 as a positional clue.
But Alice plays u2 from slot 5 next (ejection).
What should now happen ?
Bob marks his slot 3 as o3 (as a 2-away) and proceeds with his life.
If Alice would have played b1 from slot 3 (charm) then Bob would mark o4.
slot 2 (blast) would be o5, slot 4 (discharge) dupe omni, slot 1 (finesse) would be o2.
No Direct Play promise
Trash pushes are off (except if chop is revealed to be trash)
Playful positional targets playable null cards over leftmost Playable
A 4 clue is a lock as it touches all cards and reveals the 5s.
A 5 clue is a save to chop. All previously unclued cards should be marked unclued (using "x" on the note) and then proceed game normally. The player's new chop is now right to previous chop
When 2 cards cannot be distinguished by empathy :
This convention overlaps with Ejection, Discharge, Charm and Blast, choose your weapon.
When a color clue is given to Cathy which seems to target a card which cannot become playable by Cathy’s turn, the clue is actually targeting some other playable or trash card in Cathy’s hand. Bob will react with a blind play or blind discard to indicate the target of the clue to Cathy.
Note:
When a number clue is given to Cathy which seems to target a useful card to be discarded or locks Cathy, Bob should wonder:
If none of these are true, the clue is actually targeting a different card in Cathy’s hand and Bob must react with a blind discard to indicate the target of the clue to Cathy.
Note:
When a number clue is given touching new cards, and all of the (non-reversed) cards of that number are playable, but the cards would not be assumed playable from Good Touch, the touched cards are expected to play right-to-left due to Playable Number Promise.
(Reversed): However, if a number clue is given touching a single card on chop, then a Referential Discard Clue should still be entertained.
Normally when known trash is clued with number, it's a Trash Push, because it does not make sense as Referential Discard Clue, however it does make sense if there were at least 3 cards needing a save and you couldn't give a Referential Discard Clue to discard the fourth card.
Therefore, if there are at least 3 unclued cards to the left of a known trash clued by number, it's a Direct Number Discard Clue, which saves all cards to the left of the known trash.
Added by hakha3
This convention defines a new way of determining chop, instead of always discarding leftmost unclued.
Example:
r1[On Chop] b1 y5 x x
r[1] b[1] y5 x x
. Bob erases his On Chop note. He does not write a new On Chop note because this 1s clue gives a known playable card.r2[On Chop] b[1] y5 x x
r2[Play Clued] b[1] [y]5 x x
r1[On Chop] r2[Play Clued] [y]5 x x
b5 r1[On Chop] [y]5 x x
Note:
Advantages:
Disadvantages:
Let's go back to step 4 of that example, and assume that the next 3 cards that Bob will draw are r2, b5, and b1 in some order. Let's consider all six orders with and without the Loaded Chop convention. For the purposes of this analysis, let's also assume that the clue count is 5 instead of 7, so that 8 clues isn't a concern.
Assuming Alice's strategy in the current convention is to play clue red 2 eagerly: In 3/6 cases, Loaded Chop gained a clue token. In 2/6 cases Loaded Chop lost a clue token.
Assuming Alice's strategy in the current convention is to wait before play cluing red 2: In 2/6 cases, Loaded Chop saved a clue token. In 2/6 cases Loaded Chop lost a clue token. In 2/6 cases, Loaded Chop allowed Bob to gain more information before having to give Alice a clue.
Loaded Chop is therefore better than either strategy (in this particular deck where the next three cards are trash, playable, and critical in some order). In a real deck, playables and trash are more likely to be drawn than criticals, so this analysis may be skewed.
Added by @timotree3. Acknowledgement to @sjdrodge for inspiration for this convention.
The current Basic Convention for Referential Discard Clues says
A Referential Discard Clue means to discard the unclued card to right. [...] If there is no unclued card to the right, then the clue means not to discard anything. (Locked Hand)
The Referential Discard Clue Wraparound redefines this as follows:
Example where this differs from the current convention:
Giving a clue to someone who already has a play is weird because normally you would wait and give a chance to choose to sieve. In order for it to be worthwhile it should either:
Note: This convention applies to stacked clue receivers. "Stacked" means that the player has a play, while "loaded" means that they have some safe action, which could be trash.
Stacked color clues should either give a fully identified play or be impossible to give later.
r1 g[1] g5 x x
calls for red 1We agree that stacked number clues trigger a slot 1 play and a play of another previously unclued card. The precise mechanics are as follows:
If the stacked number clue touches only slot 1, then it is just a loaded play clue on slot 1 and unless it's a finesse, promises that slot 2 is trash
Added by @timotree3. Acknowledgement for @melwen for collaboration in coming up with this exact configuration.
When a reclue is given revealing a 2-away non-critical 4, it means to discard a clued card, instead of being a play clue.
Suppose all of the following conditions hold:
Then Alice discarding promises Bob an additional discard. The additional discard is his leftmost untouched card that was not chop-moved and also does not have permission to discard. Alice playing chop-moves the card that would have been given ptd.
A rank clue newly touching a card given to a loaded player is a refential play clue. It refers to the previously-untouched card to the right of a newly-touched card, biased rightward in hand when multiple cards are referred to.
This is to handle situations where cards rightward in hand can be hard to tell to play via color play clues. It is also the case that in trying to acheive good touch plays, some cards (usually 2s and 3s) will benefit more from rank info than color info while others (usually 4s and 5s) benefit more from color info than rank info.
This also diversifies the info on the clue-reciever's hand: cards positively touched with color do not benefit from additional color info but do benefit from (positive and negative) rank info.
Conflicts with the Stacked Clues Convention.
A rank clue to a player with ptd is a discard clue (revoking ptd) if it would be moving the discard leftward from the ptd and a loaded play clue if it cannot be interpreted as a discard clue to a card left of the ptd.
If a clue touches no new cards and does not fill any of retouched cards in, it promises two plays. The first is always the first finesse position. If this play could connect to a retouched card, the leftmost of these play next (as a no-info finesse), otherwise the 2nd-to-leftmost untouched card plays (as a no-info double-bluff). Since no-info finesses are expected over single-card bluffs, giving a bluff can yield information on the playability of other touched cards. If the clue reveals negative info on other cards indicating a good touch play, this play should occur ASAP but does not count towards the two play requirement.
Conflicts with No-info double bluffs.
If Alice has elimination notes for a playable card in multiple locations, one of which is her chop, and it is her turn, the playable is promised to not be her chop card. If that leaves only one location for the playable, the play is called for and her chop does not have ptd; it passes through the sieve for free. Additionally, this can be a bluff: if the play is not the elimination noted card, the card that was chop is promised to be the elimination noted card. H-group has a very similar convention.
If a referential play signal is given to a card which (for explicit/contextual reasons) cannot be playable, the card is skipped and the play signal refers to the next previously untouched card, and so on until it finds a potential playable. If none could be immediately playable, we next consider the possibility of a self-prompt-into-playable.
If the empathy + good touch value of a clue provides 2+ safe actions to an unloaded player, does not tell chop to discard, and it is clear there was no conventionally-as-efficient way to call for these actions, then this clue chop moves with no further conventional meaning.
See this gamestate for reference.
With Good Enough Clues turned on, Sodium could give purple to Hallmark turn 24, getting both of Hallmark's 2s to play and chop moving slot 1, without also asking slot 1 to play. This is because there is no conventional way for Sodium to ask slots 2 and 3 to play using a single clue.
With Good Enough Clues turned off, to be efficient Sodium first gave g4 ptd, then gave a toxic play signal t26. This only worked because no new cards had been played and slot 5 was empathy-unplayable.
See this gamestate for reference.
Hallmark draws two trash 1s in the midgame, both unfortunately passing through the sieve for free. Referential discard clues do not provide any way have both discard for one clue. A trash push would only work once g5 is playable. With Good Enough Clues turned on, 1s while Hallmark is unloaded does not promise a play: it is simply pointing out two trash cards. Depending on sodium's decision on the importance of tempo, this would have been an efficient option turn 22.
If a lock signal is given to a player who knows they could have been told about playables, but does not know where, it is a promise that all (or maybe two?) of their touched possibly-playable cards are playable right to left.
Here are (still in working progress) attempts of learning sieve more interactive
The Vanilla Direct Play Clue : What should Bob do ?
The Vanilla Color Push : What should Alice do ?
The Wraparound Clue : What should Cathy do ?
Where is The Focus ?
Where is The Target ?
Stacking Play Clues :
Finesses and Prompts
Edge Cases