Portal shields (often just called shields) are mods which make a portal’s resonators more resistant to enemy attacks.

Adding shielding to a portal contributes to its mitigation, which is the percentage of damage from enemy attacks which is blocked, making the portal’s resonators more resistant. A portal’s total mitigation (from shields and links together) is capped at 95; adding more will not increase it beyond that level.

Type Shielding Stickiness
Common +30 0
Rare +40 150,000
Very Rare +60 450,000
Very Rare (AXA) +70 800,000


The table below shows all combinations of installed shields that do not exceed the 95 mitigation ceiling (not taking links into account):

Mod 1 Mod 2 Mod 3 Shielding
Common 30
Common Common 60
Common Common Common 90
Rare 40
Rare Common 70
Rare Rare 80
Very Rare 60
Very Rare Common 90
AXA 70

AXA Shield

The AXA shield is a variant of the very rare shield. It was introduced on 15 December 2014 through a sponsorship deal with the international investment banking firm AXA, and is adorned with their logo. They are the strongest and stickiest type of shield available. AXA shields can be hacked from any portal, but are more likely to be dropped by portals at AXA locations.[source]