I'm currently wondering about the stealth skill. If I hide an item under a cloak or try to hide my appearance under a cloak: When someone tries to perceive how I look like or what the item looks like he uses perception with my stealth as difficulty. So much is clear.

But normally stealth is an action what is for example during combat is in both cases still the stealth the difficulty or does during action while the character attacks the difficulty no longer be dependent on my stealth?

I am having trouble understanding, so please let me know if I answer the wrong question.

Situation: A player character (PC) is in disguise, hiding from some stormtroopers. The stormtroopers (an adversary) are attempting to find the PC. In my opinion, the stormtroopers should locate the PC through an opposed Perception vs. Stealth check before they can attack in combat. Setting the difficulty (number of purple dice) for combat is typically based on distance and skill used. [ie. Melee attack is Average (2d), Short range Ranged (Light) attack is Easy (1d)]. The dice pool can also be affected by concealment with Setback dice. If a PC is hiding in a crowd, and the stormtroopers spot him and attack, the intervening crowd may impose Setback dice, but not really raise difficulty.

Note: I understand that there has been extensive debate on who actually rolls in opposed Perception vs. Stealth checks (PC or adversary), but I am deliberately avoiding that debate and confusion.

it is more like: The PC lets call him D is an android who is hiding his features through a cloak thus hiding that he is an android. Another PC A tries finds it strange what D does. A combat with a NPC breaks out and both PCs attack the NPC.

During this fight A gets some additional suspicions and tries to perceive WHAT D is thus trying to look under the robe.

Normally I ruled that is perception vs. stealth of the character trying to hide.

In this case the combat is raging and what I'm not sure about is if it is still the same roll (with possibly 1-2 boost dice due to the movement during combat) or if there is no roll and he sees it automatically or if it is an average difficulty roll,.....

(similar also if D is hiding an item on his body and A is trying to see during combat if D has that item on him)

I think that it would automatic to notice that PC D is an android under a cloak once the combat started...unless as the GM, you didn't want it to happen for a story reason.

As far as noticing the item, if PC A is acitively concealing it, that's an opposed Perception vs. Stealth check. If the item is just on PC A's belt, the difficulty should be Average. I would not grant Boost dice for this check.

Does D need to actively hide the item (maneuver or action) or is that an automatism?

If the person hid the object (concealed a gun under his shirt) then it's opposed Perception vs. Stealth. If you want to know if a person happens to notice an unconcealed gun on a person's hip, then it would be just a Perception check, if the GM doesn't want it to be automatic for some reason. For example, if a PC said he wanted to size up a person who walked in the room, I would automatically tell him he notes a blaster in a holster if such is displayed in the open. No roll needed. I would call for a roll only if there was some reason the blaster wouldn't be noticed - opposed if it were concealed, non-opposed if the blaster was openly on the hip but the room was very dark, choas of a bar fight, etc.

If he was walking around with the gun on his hip OUT OF COMBAT and decided he needs to hide it, no roll would be needed at the time. The roll would occur later when someone tried to use opposing Perception to notice it. If he was ALREADY IN COMBAT and suddenly decided he needed to hide his gun, then yes I would say he would need to make a Maneuver to move it some place more concealed, adjust his cloak to cover it, etc.

tnx cleared things up for my group!

With the combat scenario I would not give A any bonuses when looking at D as his attention should be focused on the NPC he is shooting at. If he is paying attention to A rather than his target or the environment then he should be receiving penalties during combat.