There are several items and abilities available which seem to allow for a character to attack while still remaining hidden. I haven't found any recommended rules on how to handle these types of encounters, so I'd like to know how this community handles them.

For reference, I'm talking about the Blaster Energy Dampener (F&D - 194) & Blaster Suppressor (Lords of Nal Hutta - 106). There are likely more but those are the two that I can recall.

Setback dice and opposed difficulty. Looking at the challenge to search for concealed weapon on a person, it could be added setback to perception (or to hit) or opposed by the target's stealth (or other relevant skill).

Opposed Stealth/Perception check is what I would do.

There are several items and abilities available which seem to allow for a character to attack while still remaining hidden. I haven't found any recommended rules on how to handle these types of encounters, so I'd like to know how this community handles them.

For reference, I'm talking about the Blaster Energy Dampener (F&D - 194) & Blaster Suppressor (Lords of Nal Hutta - 106). There are likely more but those are the two that I can recall.

Normally I'd give a Perception/Vigilance roll to detect a shooter before the trap is sprung...players tend to not like it when you just start shooting. So their detection vs the NPC's Stealth + range and cover modifiers...those might be increased difficulty, upgrades, or setback, depending.

If they miss the detection, then the NPC can shoot easily, otherwise the PCs might scramble for cover. Now the PCs know they're being shot at, but it would require a new Perception roll to find the shooter modified by Blaster Energy Dampener (or whatever). If they succeed they can target the shooter directly with the usual range difficulty and setback for cover (at least 2, but possibly more). If they fail, they can still just spray shots in the general direction, then the difficulty is simply increased, and possibly upgraded...spraying shots usually has fun negative consequences.

The roles are reversed and the PCs are sniping from cover, just flip the dice around.

When a hidden enemy is in play during combat. I usually say they can detect their location using 3 advantage or a triumph. Or spend their action to make a Perception vs Stealth check.

When an hidden enemy is in play during combat. I usually say they can detect their location using 3 advantage or a triumph. Or spend their action to make a Perception vs Stealth check.

This is great use of the dice results, adding to this, if the shooter rolls 3 Threat or a Despair then they could have accidentally revealed themselves too.