0 A.D. originally began as a comprehensive total conversion mod concept for Age of Empires II: The Age of Kings in June 2001. With limited design capabilities, the team soon turned to trying to create a full independent game based on their ideas. The game has been in development since 2000, with actual work starting in 2003.
In November 2008, the developers confirmed that they would soon be releasing the project as open-source. On 10 July 2009, Wildfire Games released source code for 0 A.D. under the GPL 2+, and made the art content available under the CC BY-SA.
There were about ten to fifteen people working on 0 A.D. around 23 March 2010, but since development started there have been over 100 people who have contributed.
On 5 September 2013, an Indiegogo crowdfunding campaign was started with a US$160,000 goal. They raised a total of US$33,251 to be used to hire a programmer. The majority of the finances are managed by the Software in the Public Interest organisation.
There is no official release date set for the finished version.
Pyrogenesis (from Greek pyr, "fire" and genesis, "origin, beginning") is the name of 0 A.D.'s game engine currently under development. It was originally named Prometheus, after the Greek mythological character who stole fire from the gods, for the use of mankind. That name was changed in 2004, after another development team advertised the use of the name Prometheus for their own game.
0 A.D. features the real-time strategy gameplay components of building a base, training an army, combat, and technology research. The game is about economic development and warfare. The game will include multiple units and buildings specific to each civilization as well as both land and naval units.
There are twelve different civilisations available, which are each represented as they were at their top. During the game, the player will not advance through time, but from village phase over town phase to city phase. Where the phases represent the sizes of settlements in history. Every phase unlocks new units, buildings and technologies.
The game features both a singleplayer and a multiplayer mode. In singleplayer mode, the player's opponents are controlled by the game. In both modes, players can choose between computer-generated random maps, hand-made scenarios, or skirmish maps as a hybrid form.
Multiplayer functionality is implemented using peer-to-peer networking without a central server. There is, however, a central lobby server which can be used to discover other players and set up a game. Players can also bypass the lobby and connect directly to each other using their IP address. When players connect to each other, one player's computer acts as a host. The host gathers commands from all players and distributes them. Sending just the players' commands reduces the amount of data that midst be sent, which reduces delays due to slow network connections. However, all connected players must calculate the entire game state from those commands, which means that the game can only be as fast as the slowest computer in the game can handle.
0 A.D. allows the player to control any of twelve ancient civilisations from antiquity.
Technologies can mostly be researched at buildings to which they are related. Technologies generally modify the statistics of certain units of buildings, to make them better at a certain task (economical, military, ...).
Starting technologies are generally cheap, but expose more advanced and more expensive technologies. Researching the right technologies at the right time is critical to win. When a technology is being researched at a building, the building cannot produce units during that time.
Most units in the game are land units.
This game features units that are both of economical and military importance. So called citizen-soldiers. This was done to reflect history, as only few people were full-time professional soldiers. Citizen-soldiers can upgrade, which makes them better at military tasks, but worse at economical tasks. Female citizens can only perform economical tasks, while champion units can only perform military tasks.
Siege units are mostly mechanical units like rams or catapults, though some civilisations can also use elephants as siege units. Siege units are effective against buildings, but too slow and expensive to be used against regular units. Healers are units that can regenerate the health of other units, however, they are vulnerable units otherwise. Traders can follow a trade route between markets and docks of a player and his allies. Traders generate resources when arriving at a market. Long trade routes makes trading more profitable, but also makes it more difficult to defend the trade route.
Next to the regular land units, there are also heroes. Heroes represent specific historical person like a famous general or political leader. These heroes are the strongest units, often having an "aura" that improves the characteristics of other units. A player can only own one hero at a time.
Ships are also considered units and can perform different tasks. Fishing ships can gather food in the form of fish, merchant ships are the nautical alternative to traders, and other ships are designed for naval battle or troop transport.
Buildings, unlike units, can't be moved once they are built.
The main starting building is the Civil Centre. This building is a rather generic building that serves multiple purposes. It can produce basic units, research some technologies (like the phase upgrades), offer protection during an early attack and act as a dropsite for all resources. The civil centre is also the territory centre. It causes a player-owned territory around the building, in which other buildings can be constructed. Other buildings are normally specialised to a certain category like dropping of resources, defending, producing units or researching technologies.
The idea of 0 A.D. started around the year 2000. At the start, it was just a modding project that would make use of the Age of Empires engine. However, different modders bumped into the limitations of using a closed-source engine, so they decided to cooperate and make a game from scratch.
Between 2002 and 2009, the game was developed in private. Only people who were accepted to the team had access to the source code. During that time, a lot of artwork was made, but it was difficult to find programmers for a closed-source model. In 2009, the team re-evaluated the development process, and chose for the open-source development model. Shortly after open-sourcing the game, the team also started to release development versions of the game.
Since open-sourcing the game, it has seen a large amount of contributors. But is still under heavy development.
0 A.D. was voted one of the Top 100 Best Upcoming Mods and Indies of 2008 by Mod DB. For 2009, it made it in the Top 100 Best Upcoming Mods and Indies again, as well as winning third place for Player's Choice Upcoming Indie Game of the Year. For 2010, 0 A.D. received an honorable mention for Player's Choice Upcoming Indie Game of the Year, and came second in that competition for 2012. 0 A.D. has been generally well received. It was voted by fans as the SourceForge project of the month for June 2012. It was voted as LinuxQuestions.org Open Source Game of the Year for 2013.