What card game does George play in this chapter (and earlier in the novel)?  Speculate on its symbolic significance.

the card game is called euchre.

sorry- George is playing solitaire; you can find the symbolism of this at the site I've linked below. The information you need is on page 101.

I would think the significance represents the central theme to this novel. Issolation permeates every character's life. Although George has Lennie, a large part of him remains in issolation. The card game reflects everyone in the novel, they all feel alone.

In my opinion the game that george plays is indeed soltaire. However it is a symbol of luck and destiny which plays a major role in card games. Similaryly it corresponds to Robby Burns poem "To a Mouse" which is the inspiration for this book. It signifies that the plans that men make, do not always go as planned and often "go wry". This is similar to the popular quote from the poem "The well laid plans of mice and men, often go wry". It shows that the Dream of George and Lennie may not bear fruit as planned.