Symbolism has many effects, such as allowing writers to add multiple layers of meaning to their work, making characters and themes more universal, and engaging readers' interest. Symbolism is the literary practice of using objects, people or situations to represent ideas that are greater than the objects' literal meanings.
Symbolism has the effect of making a literary work more complex. It endows parts of a story with at least two layers of meaning: the obvious literal meaning and the more-complex symbolic meaning. For example, a character's obsession with a watch or clock may be taken as an eccentricity, but it may also symbolize an obsession with time or an inability to let go of the past.
Symbolism allows writers to demonstrate the universal concepts underlying more specific circumstances, which helps make writing more relatable to readers. A reader who does not relate to the specific details of a story may still relate to the deeper symbolic meaning to which those details speak. This can help the reader become more engaged in a piece of writing and give him greater insight into the author's views on the world.
Symbols can change meaning or significance depending on their context. For example, a chain might represent either unity or imprisonment, depending on how an author chooses to implement the symbol and how it relates to the theme of a piece of writing.