Shields are the energy field raised around ships by right clicking. They act as the first line of defense for most ships.
Shields cost flux to keep running and generate flux when struck. This is usually hard flux, but beam weapons do soft flux damage, as do projectiles that have exceeded their maximum range and are fading out. The amount of flux generated is equal to the damage of the hit multiplied by the shield efficiency factor. Shields prevent dissipation of hard flux.
There is no way to break through shields without the shielding ship lowering its shield or striking the shield enough to force the ship to overload.
Kinetic weapons do 200% damage to shields, high explosive weapons do 50% damage and fragmentation weapons do 25% damage. Shields negate EMP damage from shots.
Each ship class with a shield has a defined shield arc width, shield upkeep flux, and shield efficiency. When activated, the shield will gradually expand from zero width to its maximum size.
A higher Combat Readiness and the Hardened Shields hullmod give a bonus to shield efficiency. The Accelerated Shields hullmod increases shield rotation and expansion speed, and the Extended Shields hullmod increases the arc. The Advanced Routing Algorithms perk of the Power Grid Modulation skill allows slow dissipation of hard flux while the shields are up, as does the Flux Shunt hullmod.
Fighters can get "under" a ship's shield (specifically, get into a position where their heading from the target ship's center is outside its shield arc) and damage its armor/hull directly. This is not possible if a ship has a 360° shield.
Shields are divided into two types: front shields, which are always centered on the front of the ship, and omni shields, which rotate with the mouse cursor. Generally, front shields have a wider arc, although the Paragon has a 360° omni shield. Front shields also expand twice as quickly.
The Front Shield Emitter hullmod converts omni shields to front shields with a bonus to shield arc and expansion speed, while the Omni Shield Emitter hullmod has the opposite effect.
Ships without a shield or phase cloak can use the Front Shield Generator hullmod to get front-facing shields.
Where possible, selectively raise your shield to stop damaging high-explosive weapons (or to protect a damaged section of hull) and lower it against kinetic weapons. This is particularly important with Omni-shields, that typically have relatively high shield upkeep costs.
Keep your shield down when not in combat, as it prevents your ship from receiving the zero flux speed bonus.
When your omni shield is facing one direction, and a shot comes in from the opposite direction, it is often faster to lower your shield and reraise it in the new direction rather than to turn the raised shield.
Shields will last 0.1 sec more after they are overloaded, so it is sometimes beneficial to stagger shots to ensure they punch through. This can be achieved with manual firing or using the alternating fire group mode.