Shield Mechanics

Author: Down To Earth Astronomy

Shield Hit Points

There are 3 main factors that affect the amount of shield hit points your ship will have: The hull mass of the ship, the stats of the shield generator and the total boosts from shield boosters.

Most information in this guide is also available in a video by Down To Earth Astronomy.

Shield Generators

Every ship has a hidden state we will call “base shield strength”. All the shield generators and shield boosters do is add modifiers to the base shield strength. This is why one ship may have more shield hit points than another even though they have the same shield generator fitted.

In the example to the right if a ship has the lowest hull mass (530.0 T) you will get the maximum shield strength bonus (+150%). If you have the optimal hull mass you get the optimal shield strength bonus and at the maximum hull mass it get the minimum shield strength bonus. Note that a shield generator will work on ship with lower mass than the minimum mass you just won’t get any higher bonus. If the hull mass exceeds the maximum hull mass the shield generator will not work.

maximum hull mass = minimum shield strength modifier 

optimal hull mass = optimal shield strength modifier 

minimum hull mass = maximum shield strength modifier

When calculating the multiplier a shield generator will apply to the base shield of a ship, first the hull mass is normalized such that the maximum hull mass is mapped to 0 and the minimum hull mass is mapped to 1. If the hull mass is lower than the minimum hull mass the normalised hull mass will stay at 1

The function for the multiplier is a power function on the normalized hull mass. The exponent of the power function is calculated like this:

Finally, the multiplier can be calculated:

This multiplier is then applied to the base shield to get the final hit points (before shield boosters are added)

<Shield Strength> = <Base Shield Strength> * <Multiplier>

Example

Let’s look at a federal corvette fitted with the shield booster shown in the top of the article. The corvette has a ship hull mass of 900T, therefore the normalized hull mass will be:

<Normalized Hull Mass> = Min(1 , (2650T - 900T) / (2650T - 530T)) = 0.8254716981

Next the exponent for the power function is calculated.

<Exponent> = Log10((1 - 0.5) / (1.5 - 0.5)) / Log10(Min(1, (2650T - 1060T) / (2650T - 530T))) = 2.4094208397

Now the multiplier can be calculated

<Multiplier> = 0.5 + 0.8254716981^(2.4094208397) * (1.5 - 0.5) = 1.129941928

The corvette has a base shield of 555Mj. This gives us the final shield strength for the shield generator.

<Shield Strength> = 555Mj * 1.129941928 = 627Mj

Shield Boosters

Every shield booster fitted to a ship will give a multiplier to the shield strength from the shield generator (not the base shield). The multipliers from multiple shield boosters are added together before being applied to the shield generator.

Example

Let’s continue the example from before where the corvette has 627 mj of shield. 3 shield boosters are fitted, 2 with a 20% bonus and one with a 50% bonus.

First the total bonus is calculated:

20% + 20% + 50% = 90%

This gives a modifier from the shield boosters of 1.9 (1 + 0.9). So the final shield strength is:

624 hp * (1 + 0.2 + 0.2 + 0.5) = 1191 mj

Guardian Shield Reinforcements

Guardian Shield reinforcements give a flat hit point bonus to shield that is not affected by modifiers from shield generators or shield boosters. This means after all the calculations above have been done, the bonus from Guardian Shield reinforcements is added on top.

Example

Once again let’s continue the example from before where we currently have 1191 Mj worth of shield. We now fit a guardian Shield reinforcement that gives 146 mj extra shield.

1191 mj + 146 mj = 1337 mj

Shield Resistance

When it comes to resistance the game uses modifiers which are applied to the incoming damage. If you are being shot at with 200 thermal damage and have 25% thermal resistance a 0.75 (1 - 0.25) modifier will be applied and you will take 150 hit points of damage.

The modifiers from your shield generator and your shield boosters are calculated separately, and we have to start with the shield boosters. The modifiers on each shield booster for a given type of resistance are multiplied together to give a combined modifier. However this combined modifier is affected by diminishing return. Everything under 0.7 will be halved, giving a theoretical upper limit of 65% resistance from shield boosters. The combined modifier after diminishing return from the shield boosters will then be multiplied with the modifier from the shield generator to give the final modifier which will then be converted back to a resistance.

Example

Let’s say we want to calculate the kinetic resistance of a ship fitted with 4 shield boosters. 2 boosters have 20% kinetic resistance and 2 have 10%. First the resistance is calculated into modifiers.

20% resistance = 0.8 modifier

10% resistance = 0.9 modifier

All modifiers are now multiplied together. remember we have 2 of each booster

0.8 * 0.8 * 0.9 * 0.9 = 0.5184

Next we compensate for diminishing return by calculating how much is under 0.7 and halving it.

0.7 - 0.5184 = 0.1816

0.1816 / 2 = 0.0908

Final boosters modifier = 0.7 - 0.0908 = 0.6092

Next we need to multiply this with the kinetic modifier from the shield generator. Let’s say the shield generator has a 40% kinetic resistance. This is a modifier of 0.6. The final modifier is:

0.6092 * 0.6 = 0.36552

This can now be converted back from a modifier to a resistance.

1 - 0.36552 = 0.63448 = 63.448%

Shield Regeneration

Every shield generator has 2 types of regeneration. The passive regen which will make your shield charge up if you have taken damage, and the broken regen which is used to bring your shield back online if it was taken offline. The rate of both type of regen is shown in the info page on the shield generators.

Passive Regeneration

The passive regeneration is active as long as you are not taking damage. If you begin to take damage the regeneration stops and will automatically start 2 seconds after you are no longer taking damage.

If you run out of power in your system capacitor the regeneration will stop. The number of pips in systems will not affect the regeneration rate, as long as you have power in your system capacitor.

Broken Regeneration

If the shield is depleted the broken regeneration cycle will start. Keep in mind that the broken regeneration rate is a separate stat from the normal regeneration rate and is often a lot faster. When the shield is broken it will begin to recharge from 0% up to 50% using the broken regeneration rate. When 50% is reached the shield will come back online and the normal regeneration rate will take over and regenerate the remaining 50%.

Note that the broken regen is not stopped when taking damage since the shots are hitting the hull and not the shield.