Hunter Thompson uses many literary devices throughout the novel Fear and Loathing in Las Vegas. His use of metaphor and simile for description purposes is shown in many places throughout the tale. He describes the difficulty covering the race as being "like trying to keep track of a swimming meet in an Olympic sized pool filled with talcum powder instead of water." Describing the effects of ether he states, "it makes you behave like the village drunkard in some early Irish novel".
Thompson also uses vast amounts of imagery in this story. Look at his descriptions of Vegas, the race, the hotels, the casinos, etc. There are also the constant allusions to Horatio Alger and the "American Dream". Alger wrote rags to riches stories about characters that came from poverty and through hard work and determination became successful. Thompson makes many allusions to this for multiple purposes throughout the story.
There is also a great deal of symbolism in the novel. Las Vegas itself is a symbol of the new American Dream, juxtaposing that of the Horatio Alger storyline. It is used to show how hard work and determination have nothing to do with success in the new America. You place your bet and hope you get lucky. It is also symbolic of American excess.