|“||Right, right. Myth and science were both true - simply different versions of the same reality, blah blah. I'd heard that lecture a hundred times, and I didn't want to hear it again.||”|
|“||How could it not be possible. In ancient times, this was common sense. Each country, sometimes each city, had its own pantheon of gods. We Olympians have always been used to living in close proximity to, ah...the competition.||”|
–Apollo explaining to Thalia how different gods exist in The Dark Prophecy.
Mythology is a collection of myths, especially one belonging to a particular religious or cultural tradition of a group of people – their collection of stories they tell to explain nature, history, and customs – or the study of such myths.
Percy Jackson and the Olympians, The Kane Chronicles, The Heroes of Olympus, Magnus Chase and the Gods of Asgard, and The Trials of Apollo all center on the presence of various mythological concepts in the modern world and the forces put in place to combat them. A recurrent theme is the emergence of a malevolent figure from mythology seeking to destroy the world, only to be defeated by modern-day heroes with the aid of their gods.
The following Mythologies have appeared in Rick Riordan's work:
Greek mythology is the collection of myths belonging to the ancient Greeks. It is prominently featured in Percy Jackson and the Olympians and The Heroes of Olympus, focusing largely on the Second Titan War and Second Giant War fought by the demigods of Camp Half-Blood and Camp Jupiter. The Greek gods are strongly tied to a metaphysical force known as Western Civilization, residing wherever the "flame" is brightest. The current epicenter of Western Civilization is the United States of America, specifically New York City.
Egyptian mythology is the collection of myths from ancient Egypt. It is prominently featured in The Kane Chronicles, focusing largely on the War Against Apophis by the magicians of the House of Life. Many of the Egyptian gods were banished to the Duat before they were released by Julius Kane into the modern world.
Roman mythology is the collection of myths belonging to the ancient Romans. It is prominently featured in The Heroes of Olympus series. When the flame of Western Civilization shifted from Greece to Rome, many of the Greek myths were reinterpreted under Roman names, thus causing the gods to develop alternate forms and forming the basis of Roman mythology.
Norse mythology is the collection of myths belonging to the North Germanic people. It is prominently featured in Magnus Chase and the Gods of Asgard, focusing largely on the einherji of Hotel Valhalla preparing for Ragnarök.
- Percy Jackson's Greek Gods and Percy Jackson's Greek Heroes are retellings of several Greek myths.
- The possibility of other myths, mythological figures, and even the non-mythological God existing is heavily implied:
- God is mentioned by Chiron in The Lightning Thief and Leo Valdez in The House of Hades.
- Thor mentions wanting to fight Jesus Christ in The Sword of Summer.
- Moses is the only foreign magician to have defeated the House of Life in a duel.
- Throughout The Heroes of Olympus, Piper McLean recounts Cherokee myths. Similarly, Frank Zhang and his grandmother believe in Chinese myths and gods.
- In Percy Jackson's Greek Gods, the titular character mentions the Indians having their own magic and gods to fight off Dionysus' forces.
- Apollo mentions Tonatiuh, the Aztec god of war and the sun, being able to bring up the sun on human sacrifices.
- Apollo and Olujime In The Dark Prophecy, mentioned Yoruba Gods , Apollo explaining to Thalia how different gods exist in .
- Apollo In The Dark Prophecy mentions the Vedic storm god Indra With Apollo on a late-night road trip in search of vindaloo.
- Apollo mention Chinese celestial dragon in The Dark Prophecy.
- Meg mentions Irish Celtic myths in The Ship of the Dead.