What happens to an "allied" initiative slot when someone (either a PC or NPC) dies? For example, let's say I have a small battle between two PCs and three (ungrouped) NPCs. Everyone rolls a simple vigilance check which results in the following order:
On the first turn of combat, Bob fires his disrupter rifle and kills a stormtrooper. What happens to the initiative order? Which NPC slot is removed from the order? The complexity of this can compound (or be simplified, depending on how you look at it) when certain NPCs have acted and others have not, forcing a sort of "process of elimination" to rationalize which slot is taken out.
I couldn't find anything in the rules about this. How is everyone else handling this, and does this need to be added into the rules somewhere?
I think it depends on how you run the bad guys in regards to initaitive. Some GMs are probably just noting at which points the NPCs get to act, and then choosing an NPC as that slot comes up in the round. Others follow more of an old-school mindset where the NPCs act in order of their initiative results from highest to lowest.
If you're doing the former (choose an NPC as each slot comes), then for the example you gave, the GM would simply pick one of the two remaining stormtroopers to act in the 1st NPC slot, and drop the 3rd NPC slot off the list.
If you're doing it the old-school way (each NPC has a dedicated initaitive slot based on their result), then if the first PC vapes the first stormtrooper in the initiative order, that slot would be removed and the second PC would get to go.
it's for something like this that I'd honestly suggest simply making a single roll for NPCs of the same type (even if they're not grouped), so as to cut down on this sort of headache and make it easier on the GM to keep track of which NPCs have gone.