§31. When one shows someone the king in chess and says: "This is the king", this does not tell him the use of this piece—unless he already knows the rules of the game up to this last point: the shape of the king. You could imagine his having learnt the rules of the game without ever having been shown an actual piece. The shape of the chessman corresponds here to the sound or shape of a word.
One can also imagine someone's having learnt the game without ever learning or formulating rules. He might have learnt quite simple board-games first, by watching, and have progressed to more and more complicated ones. He too might be given the explanation "This is the king",—if, for instance, he were being shown chessmen of a shape he was not used to. This explanation again only [manages to] tells him the use of the piece because, as we might say, the place [the role] for it was already prepared. Or even: we shall only say that it tells him the use, if the place is already prepared. And in this case it is so, not because the person to whom we give the explanation already knows rules, but because in another sense he is already master of a game.
Consider this further case: I am explaining chess to someone; and I begin by pointing to a chessman and saying: "This is the king; it can move like this,.... and so on."—In this case we shall say: the words "This is the king" (or "This is called the 'king'") are a definition only if the learner already 'knows what a piece in a game is'. That is, if he has already played other games, or has watched other people playing 'and understood'—and similar things. Further, only under these conditions will he be able to ask relevantly in the course of learning the game: "What do you call this?"—that is, this piece in a game.
We may say: only someone who already knows how to do something with it can significantly ask a name.
And we can imagine the person who is asked replying: "Settle the name yourself"—and now the one who asked would have to manage everything for himself.

ELUCIDATION

  1. This is a particular answer, by analogy, to the question asked at the end of the previous section "But what does one have to know?" (in order to be capable of asking a thing's name) Recall that in §6 he writes "I do not want to call this 'ostensive definition', because the child cannot yet ask what the name is")
  2. Chess: At least one unsympathetic commentator (possibly A. J Ayer) was baffled - outraged - by the claim that some of W.'s key insights were expressed via the analogy with chess. This is its first appearance.
  3. The place/role of 'sepia' is as a colour-word, which is a kind-word. If A sticks on the cup a label with the word 'sepia' written on it, or points at the cup and says "Sepia", this by no means provides B with the necessary information to enable him to use 'sepia' in the way that the community of users uses it. B first needs to appreciate that 'sepia' is a colour-word. We could, perhaps, imagine someone who has appreciated the category/kind/type to which 'colour' refers, without yet having learned any actual colour-words. This would be like knowing the rules of chess, knowing there is a part to be played by a king, but having not yet seen an actual piece of wood which will play this part. B "learning the rules without being shown an actual piece" would presumably involve A using such circumlocutions as "There is a piece that moves one place in any direction, and..." Perhaps we could imagine B learning the rules by studying the chess column in a newspaper. However, in either case B would have the 'k' which refers to 'the piece that...', or the 'k' that moves around the picture of the board, or is referred to in the column of code. What he would not have is the "actual piece" of wood. We can then imagine B being given a chess board and a box of wooden pieces for the first time, and asking "Lovely! Which is the king?". He is not asking "Which of these pieces has the name 'king'?" in the way that, in a purer labelling game, A has stuck one of pairs of arbitrary labels on the back of various objects in a room, put the other of the pair into a bag, takes B into the room, gives one label to B, and B asks (this game is quite boring ): "Which of these objects is labelled 'gronk'?"
  4. He is cautious about "he knows the rules" because of his later discussion of rules. He therefore prefers "mastery of the game".
  5. Stage-setting: His idea of the need for place-setting re-appears in the later phrase 'stage-setting'. An individual on his own, privately, is claimed to be unable to provide this stage-setting, and therefore to be unable to set up a language.