From the Wildfire Wiki
A list of words which may be new to you if you haven't played other similar games, or perhaps even if you have as 0 A.D. has some things not seen in other games. The descriptions here are not so much definitions of the words as explanations to help you quickly get into the game, or the community around it. To find a specific word the easiest way is probably to search for it, press the Ctrl and the F keys on your keyboard and enter the word you're looking for. Note when editing this document: please make sure to explain things in a short, and easy to understand, way. Easy to understand to be helpful to anyone who isn't familiar at all with RTS games, but short so someone who knows most of these still would want to read it to find out more about the words he/she doesn't understand.
AI = Artificial Intelligence, in 0 A.D. it means an enemy that isn't a human being but rather computer scripts/code, allowing you to play a game without the need of finding someone to play against.
In the ancient world there were not only warriors who were professional soldiers and had fighting as their job, there were also Citizen Soldiers who most of the time worked with something else (typically farming) and only sometimes picked up their weapons and went to war. In 0 A.D. we simulate this by having some units who can both do economical tasks (gather resources, build buildings, repair buildings) and fight. Typically trained at the Civic Centre and Barracks. Compare Super Units and heroes.
Civilizations (sometimes called factions) are representations of ancient civilizations. They each have a look of their own, and unique characteristics, though they share the same basic buildings and have many similar units.
Gatherer, builder rather than a fighter.
Fog-of-War/FoW/Fog of War
All areas where you don't have either units or buildings are generally covered by Fog-of-War, this means that you see objects and buildings as they were when you last saw them. If trees are cut down or a new building built you won't see it unless you send a unit there again. Units are not seen at all. Compare Shroud-of-Darkness.
A resource most commonly gathered from animals, berry bushes, fruit trees, and fields. Used mainly for creating new people units.
Nature. All objects that doesn't belong to one of the players belong to Gaia: animals, trees, rocks, etc. Animals might be hostile or afraid etc depending on their nature, but in general Gaia is Neutral towards all players.
A really strong unit. Inspired by historical persons important to the Civilization. Compare Citizen Soldiers and Super Units.
A number meant to symbolize the health of a unit/how much is left of a building.
The area around your unit/building that you can see and isn't covered by Shroud-of-Darkness or Fog-of-War. Some buildings/units have a large LOS, making it possible to see things which are far away, and some only have a smaller area they see, so it can be wise to combine units with large/small LOS.
Units who fight with for example swords and needs to be up close to the enemy.
A resource gathered from metal mines (often looks like big rocks). Used mostly to create some units.
When you play against one or more humans (and sometimes AIs as well) over the internet. Compare with Single Player.
Units who fight with javelins or bow and arrow and can fight from a distance. Some siege weapons are also ranged units. Most ranged units needs to be a slight distance away from their enemy to be able to attack them.
In 0 A.D. there are four kinds of resources: food, wood, stone and metal. Resources are needed to create new units and build new buildings.
When your units gather resources they need to leave them somewhere when they've gathered as much as they can carry, that place is called a resource dropsite.
RTS/Real Time Strategy
A type of war game where you and your opponent interact in real time (or at least close to it as you can often pause the game in Single-Player), typically with both economy and war being important.
Shroud-of-darkness/SOD/Shroud of Darkness
The black area where you haven't explored yet and can't see anything, unknown territory. Compare Fog-of-War.
Siege weapon/Siege weapons
Units used mostly to destroy buildings, but in some cases also to attack large groups of enemy units.
A game where you don't play against another human being. Often against an AI, though it could also be a sandbox game where you just explore, build, etc without an enemy.
Super Unit/Super Units
Units which are more expensive than Citizen Soldiers, and also don't have any economical abilities, they are however stronger and better at fighting. Compare Citizen Soldiers and Heroes.
Units which doesn't fight, but have other roles. Currently only the female citizen is implemented, but the Healer and Trader are also included among these.
To create a unit.
A common word for people, siege weapons, boats, and animals controlled by the player. In other words: every object in the in-game world controlled by the player that isn't a building.
A resource gathered from trees. Used both for building new buildings and to train some units.
IRC/Internet Relay Chat
A simple way to chat with several people at the same time, using either a special program/application, or a web browser. If your chat program supports IRC you can talk to other 0 A.D. players and developers by connecting to: !#0ad on irc.quakenet.org, if not just click this link to chat in your browser: http://webchat.quakenet.org/?channels=0ad
Can mean quite a lot of different things to different people, but a short, quick explanation is that it is something that you cannot only use as it is, but also look at the parts and create something new yourself with it. For example, you can not only download and play 0 A.D. you can also download the code and take a look at how the game is created, as well as edit it yourself if you know how to program.