What is the significance of the keyword "muggins" in cribbage and how does it affect gameplay?

In cribbage, the keyWord "muggins" is significant because it allows a player to score points that their opponent missed. If a player fails to count all their points during scoring, the opponent can call "muggins" and claim those points for themselves. This adds a strategic element to the game as players must pay close attention to their opponent's scoring to prevent giving away points through muggins.