Are the first and second halves of Immunity(ARM) and Immunity(BTS) linked or not? The skill does satisfy the Requirements (a saving roll is made) even if the specific Immunity wouldn't protect you. But as far as I can tell, the "If the Weapon, Skill, or piece of Equipment used in the Attack has Traits, the Trooper is completely immune to any of those Traits that cause States, refer to inflicting Wounds, or reduce the Attributes of the target. For example, State: Dead, Continuous Damage, or ARM=0" part does not refer to the type of save used against the attack at all; the newline separating it also implies it is independent from the first part. So what happens if Imm(BTS) troop is hit with Monofilament (the only type of weapon causing State: Dead which is specifically mentioned in its description), or a Flamethrower (targets ARM, has Continuous Damage Trait)? I assume this part also only applies to the specific weapons the first part of the rule works against, but it isnt clear from the wording. How would partial matches work then? The example with Plasma is kind of useless, since the weapon uses nothing that would interact with Immunity anyway - but how would, for example, Immunity(ARM) interact with Plasma? Would it ignore any potential Skills on that attack, since Plasma uses both ARM and BTS in its save? Also - does Immunity(Shock) work against Viral weapons? They use Normal ammo, and while Bioweapon trait these have refers to Shock ammo, the weapon itself doesn't use it. Does it kill 1-VITA Shock Immune models dead in one failed save? There are four examples in the rules pdf for this Skill. That is good. But the only one of them that demonstrates what happens when the Skill doesn't work only covers the specific exceptions for Nonlethal Trait and Stunned State.
The weapon table shows that weapons typically target either ARM or BTS. Monofilament weapons target ARM, and cause ARM = 0. Monofilament also causes State = Dead. You have to make a saving roll, and failing that roll puts you into a state. If you have Immunity (ARM), it becomes Normal ammo and you do not apply the state. You also ignore MODs to the save, so you ignore the ARM=0 as well. Since it's not targeting BTS, Immunity (BTS) does not apply. For plasma weapons, you treat the shot that targets your Immunity as Normal ammo, but you still take a save against both ARM and BTS. So if you had someone who fired a plasma rifle and had the BS Attack (Continuous Damage) skill but you had the Immunity (ARM) skill, the shot against your ARM would be Normal ammo but the shot against your BTS would have the Continuous Damage trait. Bioweapons apply Shock ammunition and Double Action ammunition effect to the target if it has Vita on its statline (it explicitly says this under the Bioweapon trait). Therefore, Immunity (Shock) causes you to ignore the Shock ammunition effect, but the Double Action ammo still applies.
That's obvious. But what if I have Immunity (BTS)? Monofilament weapons target ARM, and cause ARM = 0. Monofilament also causes State = Dead. Since it targets ARM it does not become Normal ammo (which is irrelevant, since it already uses that). But the line about ignoring traits is separate, and does not refer to the attribute used in the roll, so you would still ignore "ARM = 0" and "State: Dead"? This is how it is currently worded: This is how it is supposed to be worded (as far as I understand): And no need for separate Imm(ARM) and Imm(BTS) entries...
I will agree that your re-write is clearer and more concise, and eliminates the need for distinct rules between Imm (ARM) and Imm (BTS).
