So, the heroic PC, Blast Hardcheese, has snuck up on the nasty enemy guard, and needs to discreetly remove him from conscious society. Obviously, the vulcan nerve pinch is out of the question for trademark reasons, so our brave hero, goes for the tried and true classic and conks the guard on the noggin*.

Now the rules kick in. How would one best handle this?

The most straight forward solution would simply be to treat this as a melee attack. If the damage goes past the relevant threshold, the poor guard is out like light. Perhaps permanently if it wasn't strain damage. The trouble is, unless our hero is built like Beat Punchbeef and the guard is on the wimpier side of minion, this is unlikely to happen, even if you drop the difficulty for the guard being caught unawares. Some boost dice, like 2 for aiming, might help a little though.

A second option would be to, once he has managed to sneak up one the guard, let Gristle McThornbody aim with the intent of knocking the guard out, adding setback dice as normal, and perhaps needing to roll an advantage or two.

Thirdly, you could decide that this isn't combat, and as Big McLargehuge bears down on the poor guard, simply roll a brawl check against a set difficulty (perhaps a purple die per point of brawn upgrading or adding setback dice for armor?) where success knocks the guard out.

How would you play this out? Would you treat minions differently from Rivals and nemesises nemeses?

The above examples assumed an unarmed strike, but using a classical implement like flower vase or a big wooden mallet would probably work the same way. Would you treat a blaster on stun differently in such a situation?

The of course, sometimes Hack Blowfist is out for blood, and decides to use a deadly weapon like knife or a blaster at point blank range (what the rebels call "pulling a Cassian"). Would you treat this any differently?

*In real life, knocking someone over the head is unlikely to knock them out even briefly without the risk of causing serious damage. It's fine in the a swashbuckling type setting that Star Wars often dips into, but maybe not if you want to take more realistic approach.

The system created fro brawl and melee checks is designed to reflect a fair fight against an opponent who is fighting back. Such is not the case.

First, obviously stealth vs. perception to get behind him in the first place. (I assume we had that, but it is important, as it sets up the whole combat, and is essentially the poor guard’s only way to fight back.)

Now, the PC would roll a brawl check. (Or melee if he is using the tool for the job, such as a truncheon) I would say no difficulty, since it is a still opponent. He may aim twice, since there is no time constraint. Once that happens, either he is or isn’t knocked out, and if not, then everyone can roll vigilance/cool, and combat begins normal.

And that’s that.

As for your last thing:

If a person with a comparable amount of skill could do it 100 times out of 100, then it shouldn’t need a check. Knife to the throat when you have surprise? Blaster to the heart when you have surprise? You’re good.

Depends a lot on the context, but I'd probably give the benefit of the doubt to the PC. A lot might depend on the Stealth roll, I might let Advantages or Triumph be carried over into the attack to trigger weapon qualities, or maybe even bypass Soak (maybe 1A per Soak point). That said, there are plenty of times the bonk on the head doesn't go quite so smoothly, and the mechanics should allow for that too. I also think there should always be a difficulty die (not least because a DP flip allows for a Despair), but I could see making the difficulty Easy if the Stealth roll goes well enough.

Use a Light Side Destiny Point, for instant success, to progress the story and continue with narrative.

We regularly used to 'blast the door controls' to either break in somewhere or lock the doors.... worked in the movies

I love Space mutiny. One of my favorite MST3K episodes.

Suggestion, handle it like Gain the Advantage or a Vehicle Gunnery Check.

Your Brawn/Brawl/Melee is equal to the target = 2 Difficulty Dice vs. your Brawn Melee

You are stronger = 1 Difficulty Die

You are weaker by 1 point = 3 Difficulty Die

etc.

To easy? Give targets Brawl/Melee Ranks as upgrades.

I've always wondered about the Blaster To The Head. In some instances, if it's Jackie Chan you're holding the gun on, they'll be able to snatch it away or something - but generally in movies, it's usually a detriment for someone to get the drop on the other person like that.

In RPGs it's a bit harder to represent that "all I have to do is squeeze and your brains are painting the wall behind you". There's initiative, there's soak to deal with - a whole bunch of game mechanical ways to get out from under that rock when really, you should deal with that using narrative to determine the resolution. So I would go that route instead of making a PC roll to see if they knock the guard out.

3 minutes ago, Desslok said:

I've always wondered about the Blaster To The Head. In some instances, if it's Jackie Chan you're holding the gun on, they'll be able to ****** it away or something - but generally in movies, it's usually a detriment for someone to get the drop on the other person like that.

In RPGs it's a bit harder to represent that "all I have to do is squeeze and your brains are painting the wall behind you". There's initiative, there's soak to deal with - a whole bunch of game mechanical ways to get out from under that rock when really, you should deal with that using narrative to determine the resolution. So I would go that route instead of making a PC roll to see if they knock the guard out.

Executing someone in cold could very well be a discipline or cool check. Maybe a fear check. Not everyone has it in them.

Also, its not that hard to knock the gun aside and start grappling someone who holds a gun on you if the get too close. It still extremely dangerous but not extremely hard (and if you succeed, you´'re still grappling someone with a gun, which is both hard and dangerous). Even when all they have to do is squeeze the trigger, people tend to overestimate how fast their reaction time is.

As far as knocking out a guard, I might not even resort to a brawl/melee check, assuming it is just minion. I would deal with it with Triumph or 3 advantage on the stealth check.

Sneaky McSneakerson wants to sneak up on the bad guy's speech to his underlings. He sees a pair of sentries, keeping an eye out. He rolls stealth, gets 2 successes and 3 advantages, and 1 triumph. Success means no one sees him sneaking up. He uses 3 advantages to disable one guard, and the triumph to take out the other. Narratively, he sneaks up behind the one, knocks him out with a blow to the back of the head, then jumps the other, puts his hand over his mouth, and chokes him out.

Now that would not apply to rivals or nemesis. But if they are just minions? Take 'em out.

14 minutes ago, Edgookin said:

Now that would not apply to rivals or nemesis. But if they are just minions? Take 'em out.

That begs the question, how would you deal with someone sneaking up on a rival or nemesis?

It kinda rubs me the wrong way to be able to take down guards silently using only your stealth skill. Maybe some kind of combined roll using a combination of brawl and stealth?

20 minutes ago, Edgookin said:

Sneaky McSneakerson

Also, I'm gonna assume you meant Butch Deadlift.

In Warden and Martial Artist there are talents that let you choose the critical injury and you could choose something that staggers them. Then again this only for Warden and Martial Artist. This is just the first thing that popped into my head.

29 minutes ago, penpenpen said:

It kinda rubs me the wrong way to be able to take down guards silently using only your stealth skill.

See, the thing is - the system encourages you to use other skills in creative ways to get a job done. Need to climb a rock face? Use Survival to find a safer path, use coordination to nimbly Jackie Chan your way up, or use athletics to just boring ol' climb. As a GM, if you can justify to me why a skill is applicable to the task at hand, I'll most probably let you use it. So if you want to Solid Snake that Stormtrooper? Go right ahead!

Wasn't it Johnny Dangerously where they try and knock out the thug from behind and he keeps whining "Ow, ow! That hurt! Why are you doing that?!?!" or some such thing....

39 minutes ago, Desslok said:

See, the thing is - the system encourages you to use other skills in creative ways to get a job done. Need to climb a rock face? Use Survival to find a safer path, use coordination to nimbly Jackie Chan your way up, or use athletics to just boring ol' climb. As a GM, if you can justify to me why a skill is applicable to the task at hand, I'll most probably let you use it. So if you want to Solid Snake that Stormtrooper? Go right ahead!

Oh, I know and to a point I agree with you and encourage this, because it's creative and fun. Yet I feel they should be exceptions to the rule lest any incentive to make a well rounded character go put the window. I'm fine with the odd triumph rolled on a stealth check is used to take out a guard as bonus. I'm not fine with stealth becoming the default skill for knocking people on the back of the head or creative choices easily becomes a licence to ignore a characters weak stats (which should be at least as important as the strong ones when it comes to defining a character).

1 hour ago, penpenpen said:

Oh, I know and to a point I agree with you and encourage this, because it's creative and fun.

Agree with both of you. The balancing act here is being wary of letting a creative approach turn into a precedent for all future situations. You don't want the players going "b-b-but last time we just...!" At the same time, context matters because as the GM I may not want to spend much time on the guard, it could be the least important part of the mission while also providing a light moment, and you don't want failure here to completely derail what's coming. And on the third hand, you want to factor in the roll that got the PC up to the guard. So you rolled amazingly on your Stealth roll? Fine, the guard is down, with nary a peep. Oh, you succeeded, but there's some Threat? You'll have to sock him good, roll your Melee or Brawl. Oh, it wasn't enough to take him out, or you got a Despair? He goes down with a Wilhelm Scream...

So, it depends If you wanted the codified answer, it's already in the rules: Stealth is one roll, bonking on the head is another. There are all kinds of ways to get around that as has been discussed, but I'd probably deal with it on a case-by-case basis (and probably telegraph to the players that this is a "fast forward" moment). I don't think it's really possible to come up with another rule that handles every similar scenario, the existing rules already do that.

1. Minions can have pretty low strain amounts and thus a realistic knockout is an option with a brawl attack.
2. Spending advantages to go over the the little more realistic and still movie classic restrain grip and just taking two turns to knockout the guard, while using the advantages spend to keep him silent sounds good too.
3. Applying a critical to a minion automatically takes it out. It is up to the players and GM to decide that the minion is not dead, but unconscious. Players who have spend XP on precision strike don't even rely on the GM, they always can choose to have gone non-lethal.
4. Applying the correct critical strikes against rivals and even nemesis can have the same effects. Make melee attack. Ask the GM if he can aim for a staggering critical hit when attacking from stealth. Get the GM's approval, aim and hit with a critical. Knock your target on top prone, and apply in the second turn against that helpless target on top a distracted/hamstrung and winded, and your target becomes basically a floundering, but helpless victim as it has lost all its maneuvers. I strongly discharge GMs allowing to knock out nemesis characters based on GM goodwill though, those are the guys who just stand up, while rivals usually don't. The whole system gives GMs a lot of credit, so it fine here as well. And do not tell the players in advance if their move will be successful or not, this kind of maneuvers should be always risky for the unskilled, while martial artist can pull it off basically every time.

Now #4 works splendid for martial artist who can just pick the correct critical hits freely based on their all their precision strike talents, everyone else needs some GM goodwill and aim maneuvers, plus most likely the stealth advantage to actually GET the GM goodwill.
Or just one-shot everyone based on being a brawn 7 int 6 wookie marauder/doctor with pressure point, anatomy lessons, etc, there are plenty of other options. Personally I like stun duel wielded SSB-1 Static Pistols or stun sticks. Stun(8) is such a nasty attack.

I'm totally okay with minion guards being taken out by success on the stealth check alone (versus Vigilance). It's a combat the PC is going to win so IMO I'd just be burning game time by clinging to the combat mechanics. It's also not very cinematic to complicate how hard it is to take the minion guard out. In a movie, they just get taken out- no combat really ensues...unless the check is failed (ala Han sneaking up on the scout trooper on Endor).

I also allow 3 adv or Triumph on the Stealth check to take out additional minion targets. If the target is a rival or NPC then successful Stealth vs Perception just means the NPC applies the PC's Stealth dice as difficulty on their Vigilance check for initiative (if they make the Perception check or become aware of the PC in some way then Vigilance is rolled normally) (if it's multiple PCs and they all succeed on Stealth then you apply the least Stealthy PCs check as the difficulty).

Just my two cents.