0 A.D. is a free, open-source, cross-platform real-time strategy (RTS) game of ancient warfare. It's a historically-based war/economy game that allows players to relive or rewrite the history of twelve ancient civilizations, from Iberia to Mauryan India, each depicted at their peak of economic growth and military prowess. Developed using Pyrogenesis, a ground-breaking new game engine custom-built to suit this project, 0 A.D. will give players a rich and entertaining real-time gaming experience.
The Oppidum, plural Oppida (oh-PEE-dah), has a long history in the Iberian Peninsula. They were walled towns, dating back to even before the time period of the game and expanding greatly during it. They were usually built upon heights for better defensive purposes but sometimes right out on the plains, especially in the east where there may not have been heights at desirable locations near meandering rivers.