How does damage mitigation work on a portal? I heard that links and shields make it sturdier and harder to take down, but exactly what's the math behind this?
The mitigation stacks additively and is capped at 95 (=95% dmg reduction).
A portal with 4 VR shields and with 10 links doesn't have 180 mitigation, but only reduces 95% dmg. The extra shields have only the meaning of reserve shields, when some get destroyed.
Shields mitigations are :
The mitigation of the shields is a percentage of absorption of damages. A (common) shield with a mitigation of 10 will absorb 10% of the damages made by the buster. A second (common) shield with mitigation 10 will catch 10% of the remaining damages.
For example, let's imagine a burster making 100 of damages on a resonator. First common shield will absorb 10% so damages will be reduced to 90. A second common shield will absorb 10% of the 90 damages and will reduce damages to 81...
In the worst/better case with 4 very rare shields mitigation 30, a burster making 100 damages will be reduced to 24.
To compute the total mitigation of shields on a portal you have to just multiply the percentages. A very rare shield will eat 30%, to compute the effects you'll have to do
So the way of computing shield mitigation is :
To that, you have to add a defense mitigation made by links. The formula seems to be :
This will give you another mitigation to "add" (multiply) to the shield one to obtain final mitigation.
Then to compute the damages the formula is :