George is Lennie's guardian and close friend throughout the novella. George promised Lennie's aunt Clara that he would take care of him and protects Lennie from hostile individuals like Curley and his wife. George understands that Lennie is not intelligent enough to understand precarious situations and protects him by constantly giving him advice to avoid malicious individuals on the ranch. George warns Lennie about being around Curley and cautions him to stay far away from Curley's wife. George also protects Lennie by answering questions on his behalf and reiterating their escape plan if anything goes awry. George helps Lennie find work, which is difficult to come by, and also cautions him about drinking still water and carrying a dead mouse in the opening scene of the novella.
George has a tendency to get frustrated with Lennie and threatens to leave him. George continually laments about being stuck with Lennie and talks about living alone and independent. When George threatens to abandon Lennie in the opening scene of the novella, Lennie threatens to do the same thing by walking into the wilderness and living alone in a cave, which makes George feel guilty and apologize.