What is gameplay in Cribbage?

Verdict

Play begins immediately after the starter card is turned, with the pone leading the first card face up and announcing its value (Rule 7.1). This phase is the play, or pegging.

Source: Rule 7.1, Rule 1.6, Rule 1.5, Rule 7.2, Rule 1.7, Rule 7.3, Rule 7.4, Rule 8.4, Rule 8.1, Rule 8.2, Rule 8.3, Rule 8.10 — American Cribbage Congress — Cribbage Tournament Rules

Why people argue about this

People often assume that once a player lays down their card, they must immediately announce the running count out loud for it to be valid, but actually, players can hold onto their count until their opponent has pegged and then declare it at their own turn, leading to misunderstandings about when exactly counts should be announced.

Send this to your friend — argument over.

Section 4: Gameplay

Play begins immediately after the starter card is turned, with the pone leading the first card face up and announcing its value (Rule 7.1). This phase is the play, or pegging.

Each player in turn plays a single card and announces the cumulative count (Rule 7.1.c); played cards are overlapped so all remain visible and are not turned over until the hands are counted and pegged (Rule 7.1.d).
A player who cannot lay a card without exceeding a cumulative count of 31 calls "go" (Rule 1.6; Rule 1.5.e.(2)); the opponent then plays all remaining playable cards in succession (Rule 7.1.e, Rule 7.2.b).
Points earned during the play — pairs, triples, quadruples, runs of three or more, reaching 15, reaching 31, the "go," and the last card played — are scored as they occur, using the values in the scoring chart (Rule 7.2.a; Rule 1.7).
A renege is a failure to play a card that could have been played before calling "go" or "31"; a renege cannot be called when the count is 21 or lower. The nonoffending player receives two points for each card that singly could have been played (Rule 7.3).
Incorrect announcements of the cumulative count during the play are correctable if caught before the next card is played or "go" is called; otherwise the count stands, and any resulting overpeg is handled under the pegging-advantage rule (Rule 7.4; Rule 8.4).
Points are recorded by pegging on the board, advancing the rear peg over the front peg by the number of holes earned (Rule 8.1).
A hand or crib worth nothing is pegged as a zero — the pegs are simply not touched (Rule 8.2).
Pegging incorrectly to a player's disadvantage (Rule 8.3) and to their advantage, including a false claim of game, are treated as separate offences with different remedies; a false claim of game carries a 15-point backward penalty in addition to awarding the opponent the overclaimed points (Rule 8.4.a–b).
In all ACC events except match play, a player must peg out to win; failure to do so when able allows the opponent to insist the player peg out, and refusal after a judge's confirmation forfeits the score (Rule 8.10).

Section 4: Gameplay

Play begins immediately after the starter card is turned, with the pone leading the first card face up and announcing its value (Rule 7.1). This phase is the play, or pegging.

Each player in turn plays a single card and announces the cumulative count (Rule 7.1.c); played cards are overlapped so all remain visible and are not turned over until the hands are counted and pegged (Rule 7.1.d).

A player who cannot lay a card without exceeding a cumulative count of 31 calls "go" (Rule 1.6; Rule 1.5.e.(2)); the opponent then plays all remaining playable cards in succession (Rule 7.1.e, Rule 7.2.b).

Points earned during the play — pairs, triples, quadruples, runs of three or more, reaching 15, reaching 31, the "go," and the last card played — are scored as they occur, using the values in the scoring chart (Rule 7.2.a; Rule 1.7).

A renege is a failure to play a card that could have been played before calling "go" or "31"; a renege cannot be called when the count is 21 or lower. The nonoffending player receives two points for each card that singly could have been played (Rule 7.3).

Incorrect announcements of the cumulative count during the play are correctable if caught before the next card is played or "go" is called; otherwise the count stands, and any resulting overpeg is handled under the pegging-advantage rule (Rule 7.4; Rule 8.4).

Points are recorded by pegging on the board, advancing the rear peg over the front peg by the number of holes earned (Rule 8.1).

A hand or crib worth nothing is pegged as a zero — the pegs are simply not touched (Rule 8.2).

Pegging incorrectly to a player's disadvantage (Rule 8.3) and to their advantage, including a false claim of game, are treated as separate offences with different remedies; a false claim of game carries a 15-point backward penalty in addition to awarding the opponent the overclaimed points (Rule 8.4.a–b).

In all ACC events except match play, a player must peg out to win; failure to do so when able allows the opponent to insist the player peg out, and refusal after a judge's confirmation forfeits the score (Rule 8.10).

Section 4: Gameplay