In Assassin's Creed Odyssey, which civilization's world is explored by the player?

Assassin's Creed Odyssey explores the world of Ancient Greece.

The game is set during the Peloponnesian War in the fifth century BCE, mainly in 431 BCE. Players travel across regions associated with Athens, Sparta, and the Aegean world while taking part in a branching role-playing adventure. The playable character can be Alexios or Kassandra, although the game's historical canon identifies Kassandra as the protagonist.

Odyssey was developed by Ubisoft Quebec and released in 2018. It includes naval travel, dialogue choices, quest outcomes, and battles between Athens and Sparta. The title is connected to the wider Assassin's Creed mythology through the First Civilization and the modern storyline, but it takes place before the historical Assassin Brotherhood was formally established.