Dave, good job with the scenarios, I made sure to scroll down quickly so I didn't get any ideas from the other posters.
First priority is to handle the goblin coming at us. Take position behind hard cover and wait for him to come through the door. Small chance that the goblin is trained in tactics, so he will probably be nice and framed in the fatal funnel of the doorway -- allowing us to drop the hammer on him if lethal force is authorized.
Once position taken behind cover, check to make sure your buddy remembered to load the good old scattergun.
At this point, we don't know how many rounds are in it or what it's loaded with. But unless the room is a really long one, even birdshot should do the trick on this guy -- if there is no ammunition in the gun, we've got our concealed carry handgun to use on him.
Goblin #1 brings up an interesting legal justification question, at least to an attorney.
If he comes through the door without a weapon or evidences any actions that would result in deadly force being authorized (reasonable belief of imminent death or SBH, rape or kidnapping, etc, depending on jurisdiction), he cannot be summarily executed because there is no legal basis for lethal force.
Despite the fact that his buddies are almost certainly presenting an immediate danger of harm to our buddy and spouse, goblin #1 is not. At the most, we've got conspiracy to commit robbery and maybe conspiracy to commit assault with a deadly weapon. Unless in a "mob surrounding the car" type situation, conspiracy is never enough to support a legitimate claim of justified homicide.
The alternatives are to try to neutralize him without shooting him as he comes through the doorway or to shoot him (illegally). Hopefully we were able to see that goblin #1 has a weapon of some sort over the monitor, then we can drop him with a much better legal stance. We need to take care of him with speed, as the other goblins have our buddy at a significant disadvantage.
I always have OC on me when I'm carrying my gun so if circumstances prevent me from legally using lethal force on goblin #1, I may opt to neutralize him with OC and move on. Another option is to use the shotgun as an impact weapon, but remember in most jurisdictions, unless you are LE, that is the same as using deadly force, since you are using a weapon that could cause SBH. So if you're going to buttstroke him, you might as well shoot him.
Some persons might say that shooting him regardless of legal justification and moving on to save our buddy is a better idea. You didn't hear that from me, your honor.
Once we've disposed of goblin #1, we are faced with a bit of a dilemma (at least for teaching purposes).
Quickly, goblins #2 and 3 are on our buddy at the cash register, #4 is on the lookout outside and #5 is with the getaway car.
When goblins #2-5 have heard us dropping their comrade, they most likely will take off and run. They're not commandos out to take and hold this position, they're looking for an easy score -- and if one of their number has been summarily dealt with, it's gone terribly wrong for them and they'll probably bolt. These are not Marines, who never leave their dead -- these are probably your run-of-the-mill scumbags without that sort of dedication. Problem is solved.
But let's assume these guys decide to stay. The most immediate problem is goblin #2 (assumed) that is holding our buddy and spouse at bay with a handgun. Normally, if we weren't familiar with the people being held at gunpoint, we'd withdraw and wait for the police, who are trained to handle these kinds of things much better than a corporate attorney who has taken a few Insights classes.
Problem would be solved.
But this is our buddy and we've got a choice. Either we fall back and wait for the cops to handle it, or we go over the top. If we fall back, we may have to watch our buddy and his wife get wasted over the video monitor -- and relive that sequence for the rest of our days. If we go out, we might get capped ourselves.
Let's assume we go out.
At this point, unless the shotgun were loaded with slugs or 00/000 buckshot, I'd probably ditch the scattergun and go out with my handgun. Why? Well, we don't know exactly how many there are. As the old SWAT operator's saying goes, "there's always one more". We know of goblins #2-5, but what if there are #6 and 7 outside the reach of the visual monitors inside the store? If so, we are going to have to go clearing with a longarm -- not the best idea, especially in a cramped antique store.
I'd much rather clear with a handgun. And if the shotgun is loaded with bird or small buckshot, it's not going to be useful for taking out the goblins, as we are now faced with a potential hostage situation (that we decided to voluntarily enter, silly us). I know that Chuck Taylor and Naish Piazza are big on using the scattergun in hostage situations, but unless it's a slug I won't be very comfortable with a shotgun in a hostage situation.
But since this is the shotgun forum, we'll assume that the shotgun is loaded with slugs or 00 buck. Clear the doorway with the shotgun in either the extreme low ready position or the underarm assault position -- round in the chamber, safety off. Get through the doorway as soon as possible, to avoid being framed in that fatal funnel.
Make way to the front of the store as quickly as possible -- stealth is not really an issue at this point. If possible, go through the aisle with a solid wall to one side -- not the aisle with shelves on both sides. They can shoot through the shelves, so give them less angles to shoot at you.
Remember it is easier for the human body, as a weapon platform to swivel towards its weak side than the strong side. So if the position of the aisles and the cash register allow, move towards the front of the store with goblins #2 and 3 towards your weak side.
Dispatch goblins #2 and 3 first, with "disconcerting alacrity". Goblin #4, as he is outside, will be easier to handle if he comes inside since he will have to come through the doorway (another fatal funnel). Goblin #5, if he's stupid enough to leave the car and come inside, will be dealt with in the same manner.
After goblin #5 is put down, we clear the store with our buddy for the elusive "one more goblin".
Justin
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Justin T. Huang, Esq.
late of Kennett Square, Pennsylvania