I haven't had any marker troop with good CC ability before so I end up in a situation I'm not used too A speculo is in a Zeta unit back (so no LoF), the speculo declare move, using silent, and reach the Zeta base while staying out of LoF Can the zeta declare BS attack using his riot stopper as an ARO ?
No. You are never granted LoF retroactively, only Camouflage has a passage that allows to retroactively gain LoF.
Stealth, not Silent. And no, the Speculo would need to be within the Zeta’s front arc for you to make a BS Attack ARO.
Also, the effects of Stealth covers this pretty tightly IMO: STEALTH AUTOMATIC SKILL CC Special Skill, Optional. REQUIREMENTS The user of this Special Skill must be in his Active Turn. EFFECTS Allows the user to make Cautious Movements inside the Zone of Control of an enemy. A trooper with Stealth that declares a Short Movement Skill or Cautious Movement within the Zone of Control of one or more enemies but outside their LoF does not grant AROs to those enemies, even if he reaches base contact with them. However, if the second Short Skill of the Order is any non-Movement Skill, then those enemies can react normally in ARO. If the Movement of the trooper with Stealth ends in base to base contact with an enemy and declares any non-Movement Short Skill, then the enemy can only declare CC Attack, Dodge, Reset, or those Skills that can be used in Engaged state.
yeah if you have stealth and your target doesn't have sixth sense you can just move/move in contact and not trigger any ARO as long as you stay out of LoF.
Also, note that Stealth isn’t having any effect on the BS Attack - if the active trooper never enters your front arc, you don’t get to shoot them, even without Stealth.
This is a highly technical point, but there are nearly no rules* that retroactively grant LOF at all. Against a Camouflage or Impersonation trooper, you either have LOF or you don't, and just like in the case with the Speculo vs the Zeta in the OP - what matters is whether you're allowed AROs and what those AROs are. What is retroactive with camouflage is the ability to declare BS Attack, but you already had LOF if you could declare Discover previously. In the case of the Speculo vs the Zeta, the Zeta is prevented by Stealth from gaining an ARO, but it does have LOF as soon as the Speculo enters Base to Base contact. If the Speculo declares CC Attack with the second skill, the Zeta may then act on their LOF and Dodge, CC Attack, etc but the Zeta will not have LOF to any point where the Speculo was both in LOF and outside Base to Base contact. * as usual, the mandatory disclaimer: Sixth Sense provides an exception
