Multiple Shields

[BrodieSWR]

I did a search on google AND in the forums, so I am sorry if this has been discussed before, but:

How do multiple shields interact?

Let's say you have a unit with 10 Base Defence and two shields, each with 4 Parry and 0 Encumberance and 0 Defence and 10 Protection.

His ingame stats display him having 18 Defence, 10 Defence + 8 Parry.

Does this mean that BOTH shields add to the protection if the attack is <18 but >10?

Or, does this mean that the shields are used in series? If it is <14 but >10, it hits both shields, and if it is <18 but >14, it hits just one of the two?

I wish there was some information available on this...