Chess is very significant to Through the Looking-Glass, as the entire world on the other side of the mirror is a giant chessboard. Alice realizes this after she crosses through the looking glass and has an opportunity to view the terrain from the top of a hill:

There were a number of tiny little brooks running straight across it from side to side, and the ground between was divided up into squares by a number of little green hedges, that reached from brook to brook.

“I declare it’s marked out just like a large chessboard!” Alice said at last.

Not only is the terrain set up as a chessboard, she observes and meets living chess figures in this odd world. For example, she sees two castles walking around together and meets the White Queen and King and the Red Queen and King, along with other chessmen. Alice is so excited by this that she wants to be a pawn, which the White Queen allows.

Not only is the looking-glass world set up as a chessboard and filled with chess figures, the various figures are limited by their roles in a chess game. For example, the kings can only move one square at a time, and Alice as a pawn can only move two squares on her first move and one square thereafter. The queens have a definite advantage, as they are able to move across the board/world just as in a real chess game. The chess board limitations also alter the physics of this alternative world, as Alice, for example, can run and run and never get anywhere, as she is limited to one square by her role as a pawn.

The chess game also acts as a symbol of Alice's growing maturity: she grows more confident and adult as she advances to become a queen. In this world, Carroll makes literal the metaphor of life as a game.