The Portal Shield 
is a Portal Mod that increases the Portal's Mitigation.
Portal Shields are found at Common, Rare, Very Rare rarities and the Aegis variety, with rarer Portal Shields having superior stickiness and mitigation.
Community studies suggest that the drop rates of Common, Rare, Very Rare, and Aegis Shields are approximately 1 in 50, 500, 1 500, and 1 500 item rolls, respectively.
Mitigation and Stickiness[]
The base mitigation of a Portal Shield , as well as its hidden statistic stickiness, is determined by its rarity.
| Rarity | Mitigation (%) | Stickiness | XM to Apply |
|---|---|---|---|
| +30 | 0 | 400 XM | |
| +40 | 15 | 800 XM | |
| +60 | 45 | 1 000 XM | |
| +70 | 55 | 1 000 XM |
If multiple Portal Shields are attached to one Portal, each adds its full mitigation value to the Portal's real mitigation. However, the damage reduction is capped at 95% of the inflicted damage.
Portal Shields have no effect on the stickiness of other Mods attached to the Portal.
Links also increase the damage reduction. Approximately, 4 Links mitigate like a Rare Portal Shield 
; 11 Links like a Very Rare Portal Shield 
.
Aegis Shield 
[]
The Aegis Shield 
(previously AXA Shield) is a Portal Shield with the highest mitigation and stickiness of its class.
History[]
The AXA Shield item name and description strings were first discovered in the application package of Scanner version 1.65.0, and the item was released on 15. December 2014 following a press release announcing the AXA insurance company's partnership with Niantic.[1]
First-party Portals over AXA agency locations produced significantly more of the item when hacked. For some time, Portals fitted with AXA Shields dropped the item more often, although this effect has not been borne out in recent community testing. As of Update 1.80.0, the hack rate of an AXA Shield appears to be identical to a Very Rare Shield.
As of 09. July 2015, 600 000 Agents visited AXA agency locations and performed over 3 000 000 Scanner actions on their Portals. Over 5 000 000 of the item were deployed in the five months following its release.[2]
In 11. December 2017 with the release of Ingress 1.129.2, the AXA Shield was replaced with the Aegis Shield and all inventories were immediately converted to them. In addition, the stickiness was reduced from 80 to 70.[3] (The same version also replaced the MUFG Capsule with the Quantum Capsule.)[4]
In 03. December 2018, the stickiness was further reduced and now sits at a value of 55.[5]
Strategy[]
Because a Portal Shield's only role is to increase mitigation, a firm understanding of the real mitigation computation is crucial to strategically employ the item. Portal Shields , Link configuration, and the behaviour and proximity of friendly Agents configuration are all relevant to implementing a strong defence.
An attacker can trivially destroy an unshielded Portal, even if multiple Agents are simultaneously recharging it. A well-shielded Portal is easier to defend through remote recharging and gives Agents more time to react to their notifications. This protection will vanish when the attacker destroys the Portal Shields , so the interim time should be used to mobilize a local Agent to redeploy Portal Shields as necessary.
Common Portal Shields 
offer significant protection when deployed in multiples on linked Portals. Two Common Portal Shields deployed on a Portal with three Links offers about 85% Mitigation, significantly reducing the Portal's vulnerability to low-level XMP Bursters 
until the Portal Shields break.
When determining which rarity of Portal Shield to deploy, consider the density of Portals in the cluster. High-level XMP Bursters will destroy Common or Rare Portal Shields at a distance, leaving a wide swath of Portals defenceless. These areas demand redundant Portal Shields , or the increased stickiness of Very Rare Portal Shields and Aegis Shields, to hold against an assault.
Large numbers of Very Rare Portal Shields and Aegis Shields are critical elements of Ops and Anomaly gameplay. The extreme number of attacking Agents can easily destroy an Aegis Shield every two or three seconds, and experienced Agents will come to an event with hundreds of each.
References[]
- ↑ AXA/ Newsstand/Group Press Release/Document
- ↑ https://youtu.be/1h87wp3nLHs
- ↑ https://www.reddit.com/r/Ingress/comments/a3oy32/are_updated_aegis_like_wet_tissue_paper/
- ↑ http://investigate.ingress.com/2017/12/11/the-aegis-shield-and-the-quantum-capsule/
- ↑ Raw data of an Aegis Shield on the Intel map - Imgur
