Airships and Aerial combats
The very first working airship in recorded history was the "Beyonder", which Loren Venar used in his famed travels in which he opened up the first commercial rules with the Eastern empires. Up until that time, there had already been several sky kingdoms, floating fortresses and aerial transport, but never before had they actually been able to direct their flight and steer their direction. The Beyonder used a series of sails which employed wind thrust to compensate for the erratic behavior of the avernon stone's floating paths. Compared to today's vessels, it was slow, bulky, expensive and had a lot of structural flaws, but it was the first of its kind, and the history of discoveries is divided in before and after the Beyonder.
Avernon stones have been around for much longer than that. The first avernon stone was Mount Avernon itself, which rose up after Eyon Dawren sacrificed himself to purge the world of the impious rule of the eternal council.
Avernon stones are formed from granite rocks. As far as it's known, only granite can become avernon. It is known that randomly (or seeming randomly), mountains with granite deposits will change into mountains with avernon. When the avernon within a mountain is enough to overcome the mountain's mass and cause it to rise up, it is torn from its base and starts to float. No on knows for certain why or how his happens, and there is no apparent rule which allows us to predict which mountain will rise next. Avernon are a natural occurrence in all continents, but in Kartazia they are specially abundant.
Usually, when a mountain is about to be torn from its base by large avernon deposits, it starts to tremble a few weeks before it will finally rise. Because of that, it is very rare for someone to die due to a mountain's ascension. Many people, though, have lost their homes to this phenomenon.
There is a minimum size for an avernon beneath which it doesn't have enough lifting power to overcome its own weight. Avernon stones with less than 1 meter of diameter simply do not float. Greater stones are capable of floating and the mass which they can support increases exponentially.
The mass that an avernon stone can lift in kg equals to 2 to the power of its diameter, squared:
- Lifting Mass (kg) = 2 ^ (diameter ^ 2)
Likewise, the cost of an avernon stone increases with its diameter, because it is so much more difficult to find integral stones of higher mass. The cost of an avernon stone equals its volume in cubic meters times $1000:
- Avernon Stone cost = pi * (diameter ^ 3) * $1000 * 3/32
Extracting avernon stones from mountains is a very profitable occupation, but it is also quite dangerous, and a task that can only be achieved with the help of magic.
So far, it has been impossible to create avernon stones by magical means, and magically-created granite has so far never turned to avernon.
Controlling Avernon Stones
- Avernon stones float at a specific height. They rise higher when their temperature increases, and they sink when their temperature decreases. On the northern reaches, where there is always ice, avernon stones fly so low that they can be touched by a tall person. On Katazia, most avernon float at about 1 km of height.
- Every airship is thus equipped with a series of cooling and heating devices, in order to control the height of their avernon stones. It requires three operators and one engineer to maintain this equipment and to control the stone's altitude.
- When mounted within airships, Avernon stones are usually contained in a heavily protected chamber to prevent damage. Usually this chamber has 200 points of DR.
Aerial Combat Rules
Combat between airships follow the same rules as for naval combat. A few differences have to be stated, though:
- An aerial combat is much faster than a naval combat, because airships move at a much greater speed. An average airship can easily reach 100 kph, while the fastest ships do not usually go beyond 40 kph. Therefore, an aerial combat turn is only a few seconds, while a naval combat turn may take a few minutes.
- Unless noted otherwise, all airships move 4 hexes per turn. This is because all airship`s speeds are very close to each other: nearly all of them use all available wind power as thrust, and a ship couldn't go faster than the wind speed that is carrying it. This speed can be modified by a Navigator`s skill and by damage as usual. Fighters (see below) can move a different number of hexes per turn.
- In Kartazia, magical technology has allowed for the building of small flying aircrafts powered by magical instruments known as "Perpetual Mobile Keys". Perpetual Mobile Keys yield a tremendous amount of power when it comes to propelling a few people, but are inefficient for moving an entire airship. Therefore, airships usually carry smaller vessels, "fighters", which can move at impressive speeds (200 kph is not unheard of).
- The presence of fighters add new possibilities to aerial combat that are not present in naval combat. Although these fighters are unable to carry weapons (they couldn't possibly use a cannon in combat without breaking apart), they can be used for boarding or infiltration.
- Fighters have the same attributes as ships. With the following modifications:
- Fighters have no weapons. They do not fire.
- A fighter's facing has no bearing on combat. A fighter can move in whatever direction it wishes, and instantly turns to face whichever direction it needs to.
- A fighter's speed in hexes equals its maximum speed in kph divided by 40.
- When a fighter takes damage, all of its damage goes to Hull. There is no "crew" or "mast" damage.
- If a fighter is damaged and goes to 0 hp, all excess damage is applied to the pilot.
- A fighter's scale is always 1.
- The bonuses usually granted by "Navigation" skill are granted by the "Piloting" skill for fighters.
- In aerial combat, it takes 5 turns to reload a cannon. A gunner can reduce this time in as much turns as his relative skill level in gunnery. A cannon’s reload cannot go below 1.