The Hero System was born out of the necessity for a small, light tool to quickly represent the results of conflicts and battles on the masses of fighting NPC’s the characters of a Rogue Trader campaign normally deal with.

Who is that nameless soldier who kept consistently rolling 20’s?
What happened to that other nameless armsman who carried the unconscious form of their Rogue Trader back to the gun cutter after their insertion attempt was discovered by a tau listening post?
What signs did the boarding the characters did not fight in because they were busy sealing a daemon back into the Immaterium leave on those hapless armsmen and civilians who actually took part in it?
Are the characters going to notice a difference more marked than a mere drop in the Crew Population percentage on the ship’s sheet?

The Hero System is there to answer that kind of questions and use those moments to better immerse the players into the massive, living and breathing universe in miniature that is their voidship.
However, GM’s can use this system for all of the other occasions they need something similar, like when their players inevitably take interest into a random, totally unimportant and inconsequential NPC they met along the way.

As such, the Hero System is made of two parts: the status of Noteworthy for individual NPC's and the ammount of Veterancy of squads or other kinds of formations. Since the characters have at their disposal at least hundres of armsmen, it can be easier to consider them in large chunks rather than individual 10 men squads, but that is up to how much invested into role-playing the players are.

Becoming Noteworthy

After a group of NPC’s, such as mercenaries under the employment of the characters or naval armsmen, has fought in a large battle, either the GM or one of their players rolls a d10.

• 1-4 : nothing happens

• 5-8 : d5 NPC have fought with great distinction and have earned enough experience to become Noteworthy NPC’s.

• 9-10 : no Noteworthy NPC arises, but the whole group gains 1 Veterancy Point.

Noteworthy NPC’s

These people are the unexpected heroes that rise in the heat of battle; seemingly average, nameless servants of Him Who Sits on Terra who suddenly show the strength, endurance or sheer folly to perform truly heroic deeds of battle prowess and fortitude.

On the narrative side, Noteworthy NPC’s present the GM with a source of almost endless minor NPC’s to populate the characters’ vessel and to make them feel more immersed as they talk and interact with the direct consequence of the battles they both took part in. Also, Noteworthy NPC's are a perfect match for those players who like to form squads, security details and the like when they leave their ship: instead of just taking with them an X ammount of random, nameless armsmen who will be surely sent to their doom as if they were Imperial Guardsmen, they will end up with a growing selection of possible candidates to choose from to better satisfy their ostentatious needs.

Each Noteworthy NPC, at the moment of their ascension from nameless number on the ship’s crew counter to actual person, receives a shorter version of a normal character sheet : they inherit a name, surname, a small background covering at least how they became a Noteworthy NPC, the statistics of the unit they came from, like the basic Crew Rating if their unit of origin has not been modified by the Veterancy System yet, and a talent. This way, the GM is not forced to create long, detailed backgrounds for every solitary NPC the characters meet but when one is needed they have an easier solution.
I also, as a personal touch, like to add which unit the now Noteworthy NPC comes from, if any: probably, my players will not even remember they have such squad or formation in their roster, but it helps me filling up the blanks in the vast, teeming masses of people who live and work aboard a space-faring vessel.
The equipment , too, stays the same but from that moment onwards it is up to the players decide if and what do they want to do with that NPC and the others like them.

For easier deciding which background assign to whom, as it can become difficult especially when having to create multiple Noteworthy NPC’s at the same time, there is the following list.
Although rolling is surely an option, the Game Master might consider, if some of the NPC come from formations that fought in close vicinity, to choose backgrounds upon which they can build a common narrative to lend the story more credibility and weight. Also, for the sake of the story, it could be fun to ask the players to choose or otherwise come up with these NPC’s backgrounds: it is totally fine!
As an example, if two Noteworthy NPC’s are from the same squad of naval armsmen, one might have showed Dogged Defense as the other earned the Medicae Aitans by carrying the Last One Standing of another squad to the medicae bay. Of course, these options are suggestions: I added in the list those situations that I thought were the most frequent for boarding actions, planetary descents, urban warfare and the like, avoiding on purpose the heroes who might rise from vehicle or aerial combat because it is rare and when it happens usually the player characters are directly involved in it. However, GM’s and players alike should feel completely free to come up with their own ideas.

In addition to that, the pool of Noteworthy NPC's and Veteran squads is useful to choose new characters from in case of deaths!

1. Dogged Defender: the character has held their position for much longer than it was thought possible, showing immovable determination in defending the Emperor’s holy ground.
2. Giant Slayer: through sheer insanity, protection from the Holy Throne or just dumb luck the character has killed a very important enemy like a pirate lieutenant or an Ork Nob.
3. Inspiring Leader: in the face of overwhelming odds, the character let the Emperor’s Light guide them, leading a glorious countercharge to break the enemy upon the anvil of faith and steel.
4. Last One Standing: the character’s whole squad has been slaughtered, with them being the only survivor. Now, the Throne has placed upon their shoulders the burden of glorious vengeance.
5. Medicae Aitans: the character’s piety and force of will has lent them the strength they needed to risk life and limb to carry wounded battle brethren back to the medicae so they could fight another day for the glory of the Imperium… or be granted the Emperor's Mercy.
6. Reckless Measures: through occulate calibrations and litanies of fiery hatred, the character has brought their demolitionist talent to full bear, clearing enemy positions and destroying their fortifications with utmost efficiency.
7. Reckless Slaughter: the character has assaulted enemy positions and combatants with great abandon, butchering one opponent after the other in glorious slaughter.
8. Resolute Explorator: in spite of deadly danger, the character ran scout missions on the enemy positions, relaying crucial information to their superiors.
9. Righteous Hatred: as if possessed by the holy spirit of Saint Celestine herself, the character ploughed through the enemy ranks, their eyes burning with the flame of faith as they praised the Emperor’s Holy Name through sacred cleansing of heretics and xenos alike.
10. Signifer Terminus: in the darkest hour, the character raised the torn shreds of their squad’s colours, shouting in defiance as their battle brethren fought even harder for the Emperor and Mankind.
11. Spectrum Bellator: through cunning, skill at arms and unshakeable faith in the Father of Mankind, the character has haunted a portion of the battlefield, killing many enemies without being caught or noticed.
12. Strategos Tactica: whether in a moment of clarity or thanks to years of studying the venerable tomes of the Tactica Imperialis, the character managed to complete a key maneuver in the grand scheme of the battle.
13. Unfailing Aim: the character has very rarely missed their mark, their eye bringing blessed death to a great many of the Emperor’s enemies.

Once the background has been determined, the Notorious NPC now follows the normal rules for NPC’s as far as gaining experience is concerned, if they end up as recurring NPC’s in the characters’ adventures. If not, then they normally follow the Veterancy Rules down below.

Noteworthy Squads

If either at least half of the group or its leader become Noteworthy, then the whole group does. They instantly gain 2 talents and whoever is not yet Noteworthy becomes so, too.
Such evenience is perfect for those groups looking for a dedicated honour guard or specialized units for specific tasks.

Veterancy Points

Veterancy is an indicator of the level of battlefield experience a squad, unit or otherwise group of NPC’s possesses. Note that it can be applied to enemy NPC’s too, to portray troops or other opponents who have grown in a manner similar to the characters’ own soldiers, like the personal guard of the antagonist, who managed to escape with their leader, or a group of powerful mercenaries employed by the group's enemies.
When a squad or group of NPC’s gains 5 Veterancy Points , they can spend them to gain either a talent for which the meet the prerequisites, a skill or a +2 in a characteristic of the players’ choice.
When a member of said group becomes Noteworthy, they inherit all of the group’s traits, talents, skills, statistics and standard pieces of equipment.

Veteran Squads and Noteworthy NPC's

The status of Noteworthy for an NPC and the Veterancy score of the squad, group, division, company, etc they are part of are not mutually exclusive.
Noteworthy NPC's that are not reassigned by the characters somewhere else keep advancing alongside their non-Noteworthy squadmates if the whole unit progresses through time and battles: all those NPC's benefit from the spending of Veterancy, but only the Noteworthy ones benefit from their heroic status.

However, if a Noteworthy NPC is moved from an already Veteran unit to another one that is either not Veteran at all or is following a different upgrade path, they take non of the upgrades their new unit has gained in the past, but are affected by those that it will take as long as they are present.

An example

As our test subject, I am using Squads 017, 022 and 100 of the armsmen corps aboard the fuel tanker Aefestus , en route to deliver its precious cargo of promethium to Footfall.

Recently, the Aefestus has fought a battle against two pirate vessels close to the Calixian side of the Koronus Passage and, during the conflict, the venerable ship has been boarded by the dreaded White Flames who launched terror operations from their point of insertion in the Aefestus 's main hangar.
While the characters were busy repelling them from the ship's main corridors in an attempt to regain control of the hangar, the GM has been separately rolling to see how other fronts of the battles were progressing and it appears that in the Enginarium Bay the armsmen have been able to secure a perimeter. Then, the GM rolls the first d10: with a 7, d5 NPC's have been elevated to the rank of Noteworthy through heroic deeds, so he takes the note to decide their background at the next possible occasion.
In the meantime, the characters have authorized the deployment of guerrilla tactics from the hangar's crew in order to distract their invaders, the GM has rolled to determine the result of such a daring plan and, through mixed luck, it was a somewhat Phyrric success. However, when rolling the d10 for Noteworthy NPC's, the result is a 3, so no heroes are left alive when the fighting ends.
The last case is during the final push for the vessel's main hangar: the characters lead the charge in the halls of the Aefestus , clashing with the invading White Flames pirate in a storm of steel and bolt shells. After the boarding has been resolved, the GM rolls the d10, resulting in a 9: the armsmen who participated in that part of the operation gain a Veterancy Point.

Later on, when the session is done and everybody is still talking about how uncomfortably close to a TPK the boarding action looked and how great this or that action was, the GM rolls for the d5 Noteworthy NPC's from the Enginarium Bay melee.
The result of the roll is that 2 NPC's have risen to the status of Noteworthy, so the next step is to decide how: the players all agree that one of them, Christine Avregarde, should have helped on keeping the engins from exploding, adding the previously absent "Technicus Auxilia" entry to the list, while the GM likes the idea of armsman Maximilian Virge stalking pirates among the control stations, coolant vents and complex piping webs of the Enginarium Bay, choosing the Spectrum Bellator option.
So they both take the Characteristics and equipment of the Aefestus ' armsmen, each gains one talent of the players' choice. Lastly, it is decided that they come from Squad 017 and Squad 022: had they wanted, the players might have added in their notes a quick "sheet" for the two Squads to keep track of further developments, but that is entirely optional.

On the other hand, the GM knew that among those who took back the main hangar there was a unit, Squad 100, that already had 4 Veterancy Points and one Noteworthy NPC, its commanding officer Aristarcus Cassiani, who gained the Dogged Defender entry and the talent Unshakeable Faith a few sessions before, after successfully resisting the alluring temptations of a Chaos Sorcerer; adding the fifth Veterancy Point, then, makes the whole Squad 100 reach Veterancy level 1: the players, then, after some debating decide then to spend those 5 Veterancy Points to have the whole Squad 100, Cassiani included, gain +2 to their Willpower score.

I missed these when you first posted them - pretty good - they remind me of Necromunda rules a bit.

I surely took inspiration from that! I like the random potential that those tables gave

Or, you know, don't add yet another custom mechanics and just give squads/platoons XP. And at some point raise "average" stats (which affects "CR+Command" tests, which would eventually allowing them to perform at better CR than voidsmen, but then there's attrition), allow specific improvements (specialists teams with new weapon training and/or other talents), etc.

Also, there's difference between common armsmen, their officers, and separate forces like bodyguard cadre, household troops, etc. The hand-picked ones. Though ground mission teams probably should be separate and filled with dirt-siders anyway.

Of course, having great NPC is another matter - it can improve story and create plot hooks. Maybe start with pre-made qualified NPC anything in ship roles (Master of Etherics who gets bonus on Focused Augury, Master-at-Arms reels boarders, etc) not done by PC - and then new ones either have promotions (in case someone needs to be replaced) or appear as personal "Followers" much like in Deathwatch? There are always side tracks - e.g. Lord-Captain's personal transport needs a good pilot, vox operator, etc.

I like the idea, but I didn't go for that because A) it wasn't what I needed (id est: I needed quick, narrative stuff) B) a Rogue Trader ship already requires a metric load of work in order to be even remotely credible and immersive, keeping track of individual squads' experience as if they were players I've tried and got bored with it quickly enough xD (my players weren't into that kind of stuff, those who were couldn't manage the book-keeping side of it, so it failed pretty soon)

15 hours ago, Arva said:

B) a Rogue Trader ship already requires a metric load of work in order to be even remotely credible and immersive,

It's more or less a vehicle + town. Then again, the town with PCs' base needs to be mapped either way.

15 hours ago, Arva said:

keeping track of individual squads' experience as if they were players I've tried and got bored with it quickly enough xD

Obviously. IMO per-squad is excessive, unless PCs or important NPCs are directly involved abstract count by platoons/companies should be more than good enough,

Absolutely ^^

Well we have in a DH group, Arbie who when 1st loaned to us apart of an Arbite squad managed to pull of a couple of amazing shots. During his 2nd deployment we put him in an overwatch position with a long rifle, and once more the God Emperor smiled on him and his aim was true.

So it is nice to see rules "special" NPCs

My group has had more than a couple NPC's that wound up being fully fleshed out so to speak at the end of the session for one reason or another. The first one would be one of my Players' Fleet Admiral for his RT Dynasty's ships. I initially did a VERY rough draft of her ( enough to run in NPC cameo type spot ) BUT....the rolls she had while assisting his ships during a Chaos raid ( and the tactics used ) got his attention. At the end of it the raid ships were floating wrecks with minimal damage/loss to the allied side. He offered her a job with his Dynasty as his ships captain ( still must defer to him though ) to free his PC up to go play dirtside more often and still have someone competent at the helm in event of needed assistance / intervention. She worked her way up in the gameplay timeline ( its been about 200yrs now ) to Fleet Admiral of his flagship. At the end of the first session as a result of the random roll to see if she accepted his deal or not...i wound up having to put together an actual character sheet for her and have kept track of it since ( along with all the "tag-alongs" that get brought along after they get found )

Another would be the "Wing Commander" he has for his void fighter squadrons..found at a Mechanicum "processing" center for those who were hereteks, general malcontents, and offenders ( to what or whom didnt much matter to the tech-priests as long as they got paid and got to make servitors out of the prisoners ) The PC ship showed up and requested trade of throne in exchange for a press-gang to replace crew losses in previous combat. An agreement was made and the prisoners were transported to the ship. The PC RT was standing there with a force of his ship security and medicae teams to inspect and "sort" them out as to who would be good where...The Mechanicum included basic files on each that included what the supposed crimes were. The "conscripts" were sorted out into who was good at what field...then each "field" group was talked to directly by the RT ( giving him time to peruse the files of each before the discussion ) The best of the Pilot group were singled out for private discussion...in exchange for X decades of indentured service to the Dynasty...the pilots crimes were to be adjudicated...at which time the pilot was free to leave or stay on as they wished. During the flight testing one in particular stood out ( a pilot from the Lathe Forges done using the specialist profile of same in the book ) after a few extraordinary rolls / checks ( 01-04 ) He was given initial promotion to Squardron Leader...then over time worked his way up but had to do the full sheet as there were times that the PC took him with a group to meetings that inevitably wound up in combat on ground, in air, and void ( the RT was always a bit too direct for many liking...lol )

The list goes on. I do like the idea of NPC progression though....

The method our group has used is thus....

For each "engagement" ( combat scenario/session ) the NPC ( individual or unit/squad ) that survives it will gain something in XP and sometimes in gear as well in addition to routine replenishment of weapons, ammo, gear...often in the form of a single piece of upgraded equipment for use the next time )

During said engagements IF the NPC individual/squad rolls a natural 01-04 especially if there was a penalty attached on any combat or skill check....then that unit will automatically gain a +1% to the associated stat or skill allowing for a long arduous progression.

For every 500XP the unit/squad earns / spends they can increase ONE stat OR skill by +5% OR gain one EXTRA piece of kit/gear ( or an upgraded version of same ..if its a squad and you want to increase a common quality weapon or kitpiece to good quality then they need to spend 1000XP instead of 500 to give ALL squad members that better piece of kit/gear ) Also note that for whatever the unit/squad is supposed to be ( infantry, assassin, scum...etc.. ) i use double the spent XP to give access to the progression table for new skills/talents for that unit..IE..instead of gaining access to level 2 skills and talents at 500XP spent..its 1000XP spent before they can take the higher level skills/talents and elite advances are not available )

So upgrading and training the squad WILL take time and be expensive for them but will prevent the squads from overtaking any PC units they are assigned/attached to...but still gives them a chance to improve according to however the unit/squads Commanding Officer decides they need to train/be equipped.

Unless specifically stated otherwise all units i initially create will only have common quality gear..Household protection units will default to good quality, and powerful dignitaries personal squads will default to best quality.