The game is hnefatafl, or "King's Table," which simulates a Viking raid. The king is the main piece, and protecting it are 12 defenders; those pieces start the game in a cross formation in the center of a square game board. Opposing are 24 attacking pieces, which are positioned in four groups of six around the board's perimeter and which try to keep the king from getting to a "king's square," one of the corners of the board. The pieces move in a straight line across the board (not diagonally), and a piece that is "sandwiched" between two other pieces cannot move in either direction. This variant, also known as "Viking chess," had a board of 121 squares, with 11 rows of squares each.

The piece of glass was in a trench from which other items found have been dated to the 8th and 9th Centuries. Notably, Viking raiders sacked the monastery at Lindisfarne in 793. Even though most modern variants feature pieces that are either white (defenders) or black (attackers), archaeologists think that the newly found piece was part of a set that featured pieces having other colors.

Carrying out the dig were members of DigVentures, a crowd-funded organization that relies on volunteers to do the digging, literally. The mother of one of the volunteer team was visiting for her birthday and found the piece.