The Oracle is a type of Town Building. The Oracle may only be built by the High Men, Nomads, Orcs, Beastmen, Dark Elves and Draconians. A town must already contain both a Parthenon and a University in order to construct an Oracle. The Oracle's base construction cost is 500.
Immediately upon its construction, the Oracle reveals the Terrain and any Terrain Specials within a 6-tile distance of the town (including diagonals). Enemy towns within this range are also immediately revealed. Furthermore, as long as it exists, the Oracle will automatically detect any non-invisible enemy unit within 4 tiles (including diagonals).
Exploration into the nature of divine power and the gods themselves, as carried out by theologians at the University, enables some races to work out the means to exploit this power for practical applications. This results in the ability to converse with the gods themselves to a limited extent, thus gaining a limited ability to see the future. With sufficient sacrifice and a growing knowledge of various rituals, dedicated priests - known as Oracles - can see ahead in time for the betterment of their worshipers and their empire.
The Oracle as presented in the game as a large pyramid, similar to Aztec designs. Large staircases run up each side of this pyramid, all the way up to a platform at the top of the structure, where the head priest channels divine power directly through him- or herself. Worshipers may come here to seek advice from the gods on how to better their own lives, and are thus made more content with their lot.
Races and Construction Edit
Only 6 Races have access to the Oracle. They are the High Men, Nomads, Orcs, Beastmen, Dark Elves and Draconians. They are the only races that have the architectural abilities to construct it, the religious devotion required to converse with the gods, and the intellectual capacity to develop the necessary rituals.
A town requires both the Parthenon and the University before it can build an Oracle. These two structures provide the required background for ensuring that the rituals of contacting the gods will indeed work. If either structure is missing, the Oracle cannot be built. In fact, if either structure is lost or sold off while the Oracle is still in construction, the project will be canceled prematurely and cannot be restarted until these required buildings are rebuilt.
Construction of a Oracle costs 500. With such a high cost, it may be difficult to erect this structure in every town, and is not always required. However, any town experiencing a serious problem with Unrest despite the presence of all other religious structures has little choice but to build an Oracle.
Continuous Effects Edit
The presence of an Oracle in a town has three separate effects. Immediately upon construction, the first effect is applied: revealing the area within a wide radius around the town. The other benefits are far more important: a large reduction in Unrest, and the ability to detect enemy armies approaching the town from quite some distance.
Revealing Terrain Edit
As soon as the Oracle project is completed in a town, the game will immediately reveal each and every tile within a distance of 6 tiles from the position of the town.
The revealed tiles will remain permanently revealed, as occurs with any sort of scouting or similar spells. They will not become "unrevealed" even if the Oracle building is later destroyed.
Note that if an enemy empire sets up any Towns within the revealed territory at any time after the Oracle has been constructed, that town will be shown on the map permanently (or until destroyed). Again, this is the same thing that happens with any type of scouting, since the game never hides any terrain features (towns included) in a revealed tile.
Reducing Unrest Edit
Easily the Oracle's greatest benefit is its ability to reduce the town's Unrest by exactly 2 points. In other words, if the town has any Rebels (due to high Taxation, subservience to another race, or other reasons) the Oracle will turn 2 Rebels back into a normal, productive citizens.
This bonus is cumulative with the Unrest reduction given by the Shrine, Temple, Parthenon and (if it exists) Cathedral. With all five structures present, a town will have 6 fewer Rebels than it would without them - a very large reduction which can, in some situations, even allow increasing the Tax Rate without damaging the town's efficiency. If Unrest is so high that it cannot be handled by the other religious, the Oracle will likely eliminate it.
Enemy Unit Detection Edit
While the Oracle exists in a town, the town's Sight Range is increased to 4 tiles in every direction (including diagonals). This creates an invisible detection area, 9x9 tiles wide, centered around the town itself.
Any enemy unit except Invisible ones will show up on the overland map if it enters this zone, just as it would show up when coming into the Sight Range of any friendly army or town. The only difference is that a 9x9 area is much, much larger than the detection radius of any unit or town that does not possess an Oracle.
This can be very important for any town on the frontier, as it allows spotting approaching enemy armies well before battle commences. Fast armies will take at least two turns to reach a town after being detected, and most armies will take 4 turns to do so. This gives a fair amount of time for the defenses to be organized. Of course, since towns on the frontier are usually too small to build Oracles, the structure is more frequently used to extend sight-range across oceans rather than land - in vulnerable areas deep within your empire - to thwart incoming naval invasions that bypass other defenses.
Unlocked Town Buildings Edit
The Oracle is a developmental dead-end. It unlocks no new buildings for construction.
Unlocked Normal Units Edit
The Oracle unlocks no new Normal Units for construction of any kind, or for any race.
Although its Sight Range bonus is quite nifty, the Oracle's main purpose is most often its ability to reduce Unrest; on an advanced city (Tax Rate 1.5, Marketplace, Bank, Sawmill, Foresters' Guild, Miners' Guild) with two rebels, even counting the Oracle's upkeep, the net effect is 1, 8. Still, at a cost of 500, the Oracle is often a dubious investment.
The Sight Range bonus should not be overlooked however. As explained above, Oracles are often constructed in large towns on the shore-line in order to pick up incoming enemy ships well before they can land their invasion forces.
If possible, building an Oracle on the frontiers of your empire may also be worthwhile, giving you early warning should the enemy attempt to invade over land. Opportunities to do so are limited of course, since towns on the frontier are rarely developed well enough to build this structure. By the time a town is developed to the point where it can construct an Oracle, it will likely already be well behind the front lines anyway.