Disclaimer: Most of this is just pure theorycrafting on how a suppression system could work in this game.
We currently have a rather crude ‘shellshock’ type of system, which increases your gun’s sway when hit by a round or when large explosions go off around you. With grenades being thrown more and more (as more people are receiving them from drops) and the explosive charges often being lobbed into buildings when there are no grenades around, we’re seeing an increase in ‘shellshocked’ troops due to being near the explosions when they occur.
As a result, your soldier (and any other soldiers you may want to switch to in order to avoid it) will be pretty inaccurate for a little while. This currently does not affect the AI’s aim. Similarly, due to the inherent nature of the AI not having the survival instincts of a player, they will stand still and slowly turn to aim at you when you fire at them with any weapon, while most players would either find cover or immediately turn fire.
The lack of AI response (running for cover, crouching or going prone) will often lead to you being sniped by one of the members of the squad, even if you opened fire first and missed a shot or two. Both your ambush and mood is ruined.
Gamebreaking? Not particularly. Annoying? Yes.
Introducing the suppression system
When fired upon, your screen will start to turn more and more grey. Your squad AI will try to find cover and / or return fire with a 50% accuracy reduction. Your hands and gun will not shake due to the nature of the grey screen making it harder to find the target shooting at you in the landscape. The screen will fade as soon as you are no longer consistently under fire, or once you are in solid cover.
Similar to the systems used in Red Orchestra 2 and the Battlefield series, this crude suppression system would be used to force AI into cover, while forcing players to coordinate and work together to take out a threat. This gives a distinct advantage to the player catching a large group of enemies unaware, as they would have in real life.
This’ll also allow another avenue of squad progression to open up in the shape of upgrades. For example, you can implement upgrades that would allow the squad to have an additional 5 seconds before the greyscale would start creeping in. Alternatively, you can have the suppression effects fade a lot faster.