Styx (river)

The Styx river is a location in Greek mythology. Located in the Underworld, it is a river that serves as a barrier separating the world of the living from the world of the dead. It is also in this river where Thetis dipped her son Achilles, in order for him to gain the power of invulnerability. It is one of five underworld rivers; the others being the Phlegethon (or Pyriphlegethon), Lethe, Cocytus and Acheron rivers.

In order to cross the River Styx and reach Hades, a dead person must pay a fee to the ferryman, Charon. If the correct fee is paid, Charon will take the dead across. If the dead cannot afford the fee, however, they will be forced to wander the banks of the River Styx as Wraiths for eternity (or one hundred years, depending on the recount).

The greatest oath that a god can make is to swear on the river Styx. When a god swears on the River Styx, they're bound for all eternity to keep that promise or else be paralyzed for a year and a day, and even then, risk being ostracized from Mount Olympus and their duties and immortality being removed and given to another god.

Bodies dipped into the river will receive the gift of immortality; one famous example is when Thetis, mother of the demigod Achilles, dipped him into the river by his heel. This ensured he could only be harmed at his heel, a fact exploited by Apollo and later giving rise to the phrase "Achilles' heel". Styx can also be considered a goddess in her own right.

Real life references
The Acheron (meaning "Stream of Woe") is a river located in the Epirus region of northwest Greece. It flows into the Ionian Sea in Ammoudia. It was thought by ancient Greeks to have been a branch to the underworld river Styx.

Films

 * The River Styx appears in the 2010 film Clash of the Titans.

Video games

 * The River Styx is mentioned and appears in various games of the God of War franchise.

Books

 * Percy Jackson and the Olympians: Percy Jackson takes a dip into the River Styx to gain invulnerability.

Role Playing Games

 * The River Styx is a river running through the lower planes in the Great Wheel Cosmology.