Han Solo's dice were a set of golden cubes of chance that belonged to the smuggler known as Han Solo.
Using those dice, Han Solo managed to win the Millennium Falcon from Lando Calrissian. He treasured them as a sign of good fortune and suspended them within the flight deck of his beloved Millennium Falcon.
Not long after the Battle of Endor, Solo thoroughly examined the Millennium Falcon in order to refamiliarize himself with his vessel. During this examination, he discovered the dice, still suspended in the flight deck, exactly as he had left them.
These dice are only visible within a singular scene of Star Wars: Episode IV A New Hope. They do not reappear throughout the remainder of the original trilogy.