Realism

• Realism examines characters and situations as they happen in the real world. Therefore, the themes will rely on life lessons that people actually face, and they will feel familiar to you. Stories about immigration to a new country often have themes of embracing new challenges, or loss of the family and friends left behind. Stories about war can have themes of growing up, camaraderie or anguish and loss. A story about a specific ethnic group or religious group might have a theme about exploring tradition versus individuality, or feeling isolated because of barriers.
  
  

Science Fiction

• Because science fiction can encompass a lot of speculation, it can examine many themes that you may not recognize from real life. Science fiction can look into the future or past, or it can look at worldly situations in comparison to other-worldly situations. Science fiction can explore themes of total annihilation due to human folly or massive natural catastrophe. Other common themes are man versus man, human versus the unknown universe, or humanity versus technology.
  
  

Magical Realism/Fantasy

• As with science fiction, magical realism and fantasy do not have to relate to the real world or day-to-day experiences. This enables them to explore themes that deal with extremes, such as ultimate good triumphing over ultimate evil, but they can both also have common themes that the author examines in unrealistic settings.
  
  

Romance And Erotica

• Even romance novels and erotica have themes common throughout their fields. Sexual awakening is a much explored theme, in the other genres as well. Both romance and erotica also explore themes of sex and gender, race and age, and themes of sex and power. These themes have the benefit of being almost wholly universal, and you might find you recognize them.