Shield

A bubble-shaped force field surrounding a ship or a station protecting it from particle beams, railgun darts as well as radiation and other natural fenomena.

Shield only protect against fast moving particles and objects and as such are no effective against missiles and fighters and on warships they have to be combined with point defense grid.

The protection that shields offer against radiation makes them indispensable for all ships equipped with warp drive. This also presents a massive weakness as when starships shield generator is destroyed, it cannot use it's warp drive for more then few minutes, thus making it as good as crippled.

Polarisation

The shield bubble blocks particles only in one direction - either in or out. This setting is referred to as polarisation.

Protective bubble

Outward or positive shield polarisation protects the ship from incoming weapons fire and radiation while allowing the ship's own weapons to be used normally. The shield is usually tuned to let through some wavelengths so the ship inside isn't blinded.

Stealth bubble

Inward or negative shield polarisation lets all incoming radiation reach the ship's hull while allowing none to escape. This means the ship is effectively invisible to all sensors. The field only blocks outcoming radiation and thus the ship can be seen transitioning in front of distant objects, such as stars or planets. This also means that the radiation leaked by ships engines is bounced inside the bubble.

Layered shielding

Efforts to combine both settings have been done in order to enable the ships to be both "stealthed" and protected at the same time. So far, no viable way has been discovered.

Overlapping shields

With increasing shield size, the power consumption grows exponentially. This makes massive shields for larger ships like cruisers or carriers extremely energy-expensive. This problem is solved by using separate shields for different parts of ships. These shields have to be tuned to the same frequency; otherwise, they will overload each other in a very short time. Additionally, the plane of intersection of the two bubbles is a weak spot in the protective barrier and as such is often targeted. The reason for this weakness is that in this region, the frequency of both bubbles is distorted, which leads to fluctuations in nearby region of both bubbles. If successfully exploited, attack at this point can lead to overloading of both generators.

The intersecting plane is nearly completely flat on both bubbles. Thanks to distortion, this part of either bubble is basically non-existent. It can create slight signal interference, even in cables, but modern computers are programmed to suppress this fenomenon.

Discovery

After the discovery of the derelict alien base on Io, most of the ships located there were reverse-engineered and the viability of this technology was confirmed leading to massive research funding. Later in the research of Warp drive, it was discovered that the shield technology would be an indispensable if the drive was ever to be used for transport of people.

Shield hardness
A whole number between 0 and 1000 that represents the amount of energy above the normal background radiation the shield is able to absorb before needing to be cycled off.