I don't think this sort of communication from guessers to clue giver is in the spirit of the game (at least in my play group). However, inflating later clues is a reasonable approach! It's just that I don't think you're allowed to communicate the amount of inflation. Guessers must determine whether people 5 has slack to allow additional guesses on previous clues.

You're free to add additional prohibitions on communication as a house rule I guess, but the only prohibition in the rule book I've seen is that the clue giver's speech must consist exclusively of clues (and private consultation with the other clue giver). The clue giver is free to adjust their clue in reaction to anything they hear, and guessers can speak freely.

Important: the clue giver cannot acknowledge the instruction during gameplay. That would certainly extend beyond giving a clue! The guessers must know that their clue giver can play this way prior to the game commencing.

Edit: I just consulted the rules and this is the most relevant section:

> If you are a field operative, you should focus on the table when you are making your guesses. Do not make eye contact with the spymaster while you are guessing. This will help you avoid nonverbal cues.

> When your information is strictly limited to what can be conveyed with one word and one number, you are playing in the spirit of the game.

The author's use of the pronoun "you/your" switches from field ops in that first paragraph to spymasters in that second paragraph, confusingly. With that in mind, it boils down to this: field ops cannot seek non-clue information from spymasters, and spymasters cannot convey non-clue information. The strategy I'm suggesting involves neither!

If you take this idea of communication restrictions to the limit, you could imagine the guessers identifying N sets of cards by a single word each as they discuss their guess. The clue giver listens, then uses the clue that identifies the correct set of N cards.

You really just need an algorithm to generate unique sets of 8 or 9 from the whole board, and identifies those sets by a word.

Yeah it's interesting to take these ideas to the extreme... even at the lower end I don't like it, I think zero communication outside of clues is the best way to follow the spirit of the game. But a little bit of banter and "kibitzing" is what makes it fun too.

I played in a Codenames tournament at CGE's stand at GenCon, and they forbid guessers from communicating at all. Officially, its supposed to be just the clue and number and nothing else.

Of course, I never play this way in my own games

How do guessers arrive at a consensus about what card to touch, if they are forbidden from communicating at all?

officially its a 4 player only game, at least at the tournament. I never do it this way myself though

The communication is only necessary/important if people haven't set this as a convention in the first place. I'll say that prior to ever looking at my clues: "I will give you higher numbers than what I said if you miss by more than 1. THe number I pick will always be high enough as to allow you to, with the +1 guess you get for free, make guesses on all the words I was hinting at.

There's also all kinds of not necessarily intended communicaton from the guessers in the fact that you can listen to which words they were considering and didn't pick. Nothing in the game attempt to say that you should not consider, say, whether they were going in the right or wrong direction in their guessing, but it sure can make a difference in how to approach later clues. If they were being very wrong, there might be a need to double up on words that you intended, and that your guessers missed.

In the same fashion, nothing in the game saying that I cannot listen to those guesses as a member of the other team, whether guesser or spymaster, and then change behaviors to make sure we don't hit words they considered as candidate words without very good reasons. Let them double dip on mistakes, or not make their difficult decisions easier. It's not as if the game demands that everyone that isn't currenly guessing should wear headphones to be sure they disregard what the other team says or does.

You can of course play however you want (and I certainly think this is clever), but imo this is likely against the spirit, and perhaps letter, of the rules.

The rule on giving clues is:

"If you are the spymaster, you are trying to think of a one-word clue that relates to some of the words your team is trying to guess. When you think you have a good clue, you say it. You also say one number, which tells your teammates how many codenames are related to your clue." (emphasis mine).

The rule states that the number should be the number of words related to the clue. There is later provisions allowing you to use zero and infinity, but outside of these carve-outs (and imo the "allowed" language is telling here, since it implies any other number not equal to the number of words is not allowed) I don't think this is legal.

We always allow any number when we play, because part of the thinking is we cannot be sure what the spy master has in mind. Of course, the number is related to the clue but possibly also to the game history up to that point. The teammates and opponents might interpret it wrong, and that’s OK. Infinity is typically used when there is enough info in principle to finish the game and a high risk if you dont; zero is super rare. We do tend to have very aggressive bids with tenuous connections, and 4 or 5 for a clue word are used in most games. Often, they don’t all work out in a single round, but on some lucky boards or in spousal teams, they occasionally work well.

You have a valid point, to which I'll concede. The rule book gives an example (spanning pages 4-5) where a guesser uses prior clues to select a card while the count is still within the number stated by the spymaster, but I suppose an allowance for guessers to deviate in this way does not also imply that spymasters may deviate in this way. Mea culpa!

Taking this a step further, given that it's well-known that a clue is deemed invalid when it pertains to cards in certain non-definitional ways (sounds-like, number of letters, etc.), it seems extremely reasonable to call a clue followed by N invalid if it doesn't pertain to N cards in a definitional way.

Indeed, a good Codenames-playing bot should know how to do all of this, in addition to using its LLM to generate great clues.

Yeah, in fact we tend to play without a limit on the number of guesses, just to avoid this sort of loophole. In variants like Codenames Duet I think there's also no limit on the number of guesses.

Another thing the guessers can do if unsure about one of the tiles from the last round, is to tell the clue giver which tile they think it was. The clue giver then tries to give a clue that either tenuously links to it or clearly excludes it. That can give the clue more scope for linking to several other words. It risks giving information to the other team though so is more of an final turn play.