I come from 4e DnD, where monster blocks are entirely self contained and don't require any reference to books.
 
For this reason, I don't mind that choppa damage is inconsistent, I just use the value given. I'm also not a huge fan of giving monsters traits from the book, because this requires looking up several things just to use a monster whose description should really only be less than half a page.
 
Things like 'unnatural toughness(2)' and 'fear(2)' are pretty straightforward, but I just find myself adding some bonus damage on the charge when I see 'brutal charge' rather than wasting time to look it up.
 
I think I'm spoiled from other rpgs I've played, and I think being spoiled is a good thing. When I create monsters myself I'll probably just list the abilities rather than giving traits and letting someone else look them up. For example, in an Ork entry, I'll just write (+10 WP tests per ork within 10m).

Kestral X RRV:
Rapid Response Vehicles play a special role in the Kestral armed forces. They are used as patrol vehicles and first response vehicles by special teams such as Storm Troopers and Field Medics. The RRV is an oversized four wheeled lightly armoured road car.
Type: Wheeled                                                                                              Tactical Speed: 20m
Cruising Speed: 85kph                                                                Manoeuvrability: +10
Structural Integrity: 25                                                                Size: Enormous
Armour: Front 20, Side 16, Rear 16
Vehicle Traits: Enclosed, Rugged, Wheeled Vehicle
Crew: 1 Driver, 1 Gunner (Pintle-mounted Weapon)
Carrying Capacity: 5 Imperial Guardsman plus gear

Weapons:
Pintle-mounted weapon (Choose one of the following).
• Heavy Stubber (100m, -/-/8, 1d10+4 I, Pen 3, Clip 80, Rld 2 Full)
• Missile Launcher (300m, S/-/-, *, Pen *, Clip 1, Rld Full)
• Automatic Grenade Launcher (80m, S/2/4, *, Pen *, Clip 20, Rld 2 Full)

Options:
The Pintle-mounted weapons sometimes have a Gun Shield  (See page 121 HotE).
A Medi-back variant was introduced to transport injured soldiers quickly to a field hospital, these models sacrifice the Pintle-mounted weapon for the capability to hold two stretchers and an Advanced Medi-kit. These models have their carrying capacity lowered to 2.

Civilian Road Car:
The Road Car is a vehicle used by those who can afford one. They can comfortably get you from point A to point B.
Type: Wheeled                                                                                              Tactical Speed: 18m
Cruising Speed: 75kph                                                                Manoeuvrability: +10
Structural Integrity: 16                                                                Size: Enormous
Armour: Front 15, Side 10, Rear 10
Vehicle Traits: Open Topped, Wheeled Vehicle
Crew: 1 Driver
Carrying Capacity: 4 passengers

Small Industrial Flatbed Truck:
These commercial vehicles are used to transport loads throughout the city. Insurgents have been known to add some extra armour and mount on or two machine guns on top of them.
Type: Wheeled                                                                                              Tactical Speed: 15m
Cruising Speed: 65kph                                                                Manoeuvrability: +0
Structural Integrity: 26                                                                Size: Enormous
Armour: Front 18, Side 16, Rear 16
Vehicle Traits: Open Topped, Rugged, Wheeled Vehicle
Crew: 1 Driver
Carrying Capacity: 2 passengers and 5 metric tons of cargo
 
 

Hi board,
 
I am usually not a nitpicker when it comes to typoes. But when I got my copy of "EotI" yesterday I almost immediately flipped back to the "Credits" section to make sure there was an entry under "Editing and Proofreading".
 
It's been a while since I've seen so many errors in one paragraph of a professionally produced book.
 
Page 8:
 
Line 4
"the war to control the Calyx Expanse would have taken to complete"
--> probably missing: "much longer".
 
Line 5
"might not have completed" --> this is only a matter of taste, but repeating verbs displeases the sense of aesthetics of every Eldar Lord.
 
Line 7-8
"Severus's greed his greatest limitation"
--> His greed even swallowed "was" or "proved to be" or whatever verb was omitted.
 
Line 15
"as the descendants of [...] Severus descended into"
--> this might have been done on purpose, but sounds terribly awkward. IMO.
 
Line 16-17
"Without their Warrant of Trade or the capacity to claim new domains and titles."
 
--> The capital letter and the fullstop indicate this is supposed to be a complete sentence, the lack of a verb speaks against it. Or it is a continuation of the preceeding sentence, but then why the fullstop before "Without"?
 
Five mistakes in an introducing  paragraph of 17 lines. Not bad!
 
Why am I being such an ass? Because it makes for a terrible first impression and makes me look out for more mistakes. So please, at least proofread the first paragraphs! And I am not even a "native reader".
 
Or am I the only one who is bothered by this?

It can (and, regrettably has) lead to arguments that I've seen - mostly if the Rogue Trader refuses to listen to other players. However, unlike a Commissar, things are much more blurred.
 
All the players are very powerful archetypes, most of whom are on the ship because they're working with the Lord-Captain, not for him.
 
A Rogue Trader represents the Dynasty, but a Navigator represents a Navis Nobilite family, whos holdings, wealth and general influence make most Rogue Trader Dynasties look like paupers, and is vital to the operation of the ship.
 
The Explorator (a) represents the Adeptus Mechanicus - one of the most powerful factions in the Imperium - and is the only man who can...you know...make the ship go.
 
A confessor represents the ecclesiarchy (same) and probably commands the loyalty (or at least fear) of the crew every bit as much as the Rogue Trader.
 
The Astra Telepathica are another extremely powerful organisation, and - more importantly - the Astropath is in a direct position to inform someone if he doesn't like something the Rogue Trader is up to. Equally, only he knows what message he actually sent. I've seen Astropaths smile and nod in an especially one-sided "planning discussion" and then (with the Seneschal's tacit approval) send instructions to minions which are almost the exact opposite of the Rogue Trader's "orders"...
 
The Arch-Militant, Seneschal and Void-Master don't have massive legal or financial authority, but sit between the Rogue Trader and his troops/financial resources/ship, so are perfectly capable of overriding him when he's blatantly wrong 'in the best interests of the Dynasty'. After all, there's a sizeable noble household outside the confines of the ship, and whilst the current warrant holder, the Rogue Trader isn't necessarily the head of house X.
 
The Arch-Militant, for example, doesn't have much direct authority. But he does tend to have a very large gun, which is an acceptible substitute in most debates. Besides which, if he's in charge of the Rogue Trader's armsmen contingent, he's the guy the Rogue Trader has to convince to get someone compelled to do something 'at gunpoint' - if he's a PC, he's perfectly capable of pointing out that the Rogue Trader is being a cretin and should listen.
 
 
 
Agreed. Rogue Trader, or Ascension, may have a character who is distinctly 'in charge' (Warrant-Holder and Inquisitor respectively) but they are very much 'first amongst equals' of a group who are all above the law in their own way. Only War is no such thing - Kelly's Heroes-style Penal Units aside, the players are an integral part of a military and should act like it.
 
Just as an aside, whilst I don't 'ban' Commissars, I tend to reserve them for when the PCs are playing a 'command squad' - he can feel free to shoot platoon members outside the core PCs. I tend to advise them to stick with Terrify rather than Summary Execution.

I has noticed this same Commisar/Paladin blowback issue from a group I used to play with years ago. I realised over time that these people were not humorous a**holes they were really just, well, a**holes! I stopped playing with them right about then I seem to remember. I agree with the above: If your players can't handle the hierarchy of a military setting then maybe they shouldn't be in one! 

I've been playing awhile now, and I'm largely convinced that the current rules for Medicae are poorly made and not working as intended.
 
First Aid allows the medic to make a medicae test with -10 per point of Crit Damage. It takes one turn and heals a fair bit. A modest medic can easily do in one turn what would take a heavily or critically wounded character days or even weeks. You probably have a 40% chance of success or better. You can do this max 1/day per person.
Extended Care allows the medic to make a +10 test on multiple people. It takes a full day, and heals a fair bit, but if you fail patients start taking highly variable amounts of damage, and heavily or critically wounded patients are likely to die.
 
It seems to me that you would almost never want to use extended care. It's much safer to just make a first aid check every day, and takes far less of the physician's time. Even with a high medicae skill and a single patient, you're probably about 10% likely to kill a heavily/critically damaged patient just by taking care of them, whereas leaving them alone or just giving them 5 seconds of attention per day is perfectly safe and can heal about as much.
 
Suggested Fixes
No possibility of damage from extended care: It's ridiculous that natural recovery with critical damage is safe, but taking your time with a moderately wounded patient has around a 1/10 chance of killing them.
Nerf First Aid (Maybe): It seems to easily and quickly produce miraculous recoveries, which renders extended care largely obsolete. You could limit it to one use per deployment/mission, rather than one per day, or don't allow its repeated use for the same old injuries. This would reflect that first aid is a quick patch for the short term problems, but some injuries require longer term attention.
 
If you apply "No possibility of damage from extended care" it becomes useful for critically wounded patients who might otherwise take weeks to recover. If you also "Nerf First Aid", then Extended care becomes the main source of downtime recovery for critical patients.
 
Note, I assume that you can't retry failed first aid checks before 24 hours, but even if your group does it differently the above should still apply.

If they keep throwing grenades, eventually somebody is going to roll 17, 18, 19, 20 and that will really hurt, especially if one of those is a 10.
 
Mortars.
 
The follow-up for flame is very nasty. Unless you have really good WP you;re pretty much dead, And it will affect many people at once, note.
 
Plus it might set the cover on fire.

Welcome to real combat.
 
Pinning is not a way to kill the enemy but to protect yourself. So if the enemy is pinning over and over, he's not killing you. Since you're behind cover all the time. So why is he bothering? He should be trying to _flush you out of cover_, not _force you into it._
 
"as this takes quite a bit of ammo"
 
Actualy by RAW you can Pin people with 2 laspistol shots a round.

Yeah, they have a tendency to obscure the rules behind a barrage of flavour text and really unclear terminology. I'm not entirely sure how FFG would feel about me giving you a detailed breakdown of the rules here, but here's a stab at an overview:
Resolving Damage
A successful attack inflicts Damage on the target. How much Damage is inflicted depends on both the properties of the attack and the properties of the target.
Damage Soak
Most attacks have both a Damage value (dice roll + modifiers) and a Penetration (Pen) value.
Most Targets have both a Toughness Bonus (TB) and an Armour Points (AP) value.
Subtract the Pen of the attack from the targets AP. Add the target's remaining AP (if any) to its TB. Call the value you just arrived at the target's Soak (not the the rules will, mind, but it's nice to have a term for this value). Resolve the Damage value of the attack. Subtract the target's Soak from the Damage value of the attack. Subtract any remaining Damage from the target's Wounds. Wounds
Most entities have a Wounds value. Wounds are basically Hit Points, which I'm assuming you're both familiar with. However, when a target runs out of Wounds it doesn't keel over instantly as you may expect, instead it starts suffering Critical Damage.
Critical Damage
When a target runs out of Wounds to subtract Damage from, it instead starts adding Critical Damage effects. These stack, so if a target already has 4 points of Critical Damage and receives another 6, it has 10 points of Critical Damage (AKA hilariously gory death).
 
 
Note: Embrace the term Soak, it will make your life a lot easier. Also consider thinking in terms of Attack Strength and Damage instead of just Damage, because calling it Damage both before and after reducing by Soak is a great way to facilitate lots of miscommunication and general confusion.

Well that's just another thing that needs to be fixed, then.
I'll be honest, I had completely missed that line, but I think there's strong arguments that it should be waived in many cases. It's about like the Manipulator Mechadendrite itself, which doesn't clarify at all when the bonus applies, other than Strength-based Tests; this would include situations like the aforementioned Intimidate and Athletics. I can see an argument for how a Manipulator Mechadendrite would help with Intimidate, but not overly moreso than any mechadendrite would - but Athletics overall? Oh wow, no. Unless anyone wants to argue that Manipulator Mechadendrites help you swim.
And at the same time, it would make perfect sense that if you have two Manipulator Mechadendrites to tether yourself to the ground and use as bracing, and another two to help you lift something, they would all apply, which runs completely contrary to the general rule you cited.
Another good example would be the Strength increase from Best-Craftsmanship Bionic Arm. It applies +10 Strength. But going by the aforementioned general rule, it wouldn't become +20 if you had two Bionic Arms. The +10 Agility for fine manipulation with a Good-Craftsmanship Bionic Arm, I can see how that wouldn't stack, but if you have two extra-strong arms, then you have two extra-strong arms, not just one.
Nevertheless, it is RAW. It's futile to argue on the boards, because in the end, it's yet another thing to raise with the GM.
I always get the feeling that I'm starting more conversations with my GM with "I would argue that..." than in any other system.
Anyway, no, I can't cite a place where terminology is specifically explained (such as "Strength" vs. "Strength-based". It's just implied by wording and (relatively) consistent useage throughout the books. FFG is notoriously bad at proof-reading and sometimes they slip up when writing the rules, leaving room for quite a lot of ambiguity. Further annoyance is added to this by being absolutely balls-to-the-walls terrible at updating the "Living" Errata(s).
They somewhat make up for this by having a very good Rules Questions section where you can submit mails directly to them and have questions cleared up. But it's nevertheless an annoyance.
Sometimes, I think they should write a Terminology, Key Phrases and Keywords-document. Partly for us, the customers, but also as a reference document for their own writers.

Remember the old joke?
"What do you call a lasgun with a laser sight? Twin-linked."

Well that's the problem, our culture is using it wrong. It's never been about "stealth" as it exists in our cultural conciousness, it's something created by modernist Hollywood, nothing else. In reality, you usually do not silence sniper weapons, simply because silencers tend to interfere with more important aspects (velocity, accuracy, etc), while also being incredibly ineffective.
Oddly, the most common "sniper rifle" in the TT/fluff is actually ratlings with needle weapons. It's actually odd that the Ratlings in Only War starts with either Sniper Rifle or Long-Las, instead of a Needle Rifle. If things had been a little different, Ratlings starting with Exotic Weapon Proficiency (Needle) could actually have been a pretty nice aspect, but it's possible that they worried about the possible balance issues with that (although I don't see why they would be very big, if we consider the monstrosities we've been able to construct in this thread).
The lack of the whisper-bolt discharger in Only War may be deliberate, but I just don't see the rationale for it. It is more likely that at some point, they have to stop adding stuff, as the book starts swelling out of proportions fairly quickly, if you take all the various knick-knacks mentioned in the entire line into account.
As for being able to silence/conceal a lasweapon; Tenebrae's post makes sense in reality, but not so much in the context of the universe. Las-shots are clearly visible, similar to blasters in Star Wars, and I'd think that the visibility itself would be more interesting to discuss than the speed at which light travels, simply because there's no reason for them to fire the lasweapons in a way that would reveal the light at all.
I prefer to think of it like this; The reason they're tuned to the visible spectrum is because the Imperial Guard has no idea what they're doing, and when the Adeptus Mechanicus tunes the weapons or builds them, they are set to red FOR THE GLORY OF THE OMNISSIAH.
And yes, the reason there's a loud and audible *crack* when firing lasweapons is because they ionize and superheat the air it travels through. I also like to imagine that there's a big *pew* coming from the weapon itself, but that's just me.
As for just how Whisper-Bolt Dischargers work, here's the fluff text:

How do they work? Well, clearly, the resonance flux-capacitor have reversed polarizations, resulting in reverse ionization within hydrogen-oxygen atmospheres, while re-tuning the laser-spectrum of the focusing lenses of the forward battery to appear invisible to the naked eye. Unless you're a cat.

Also, as this is a sci-fi theme with a government and a military whose moves are not always based on sense, sound intel, any of that, in Stargate SG-1, they gave Daniel Jackson, a full civie, the same armor, a P-90 (and he got trained with it, in the downtime), a pistol, and all the stuff, same as O'Niel and Carter. Teal'c wears similar armor/apparel, because his armor isn't appropriate to many missions, but he keeps his staff weapon, and carries a Zat, as they are both better guns than everyone else gets. Later, many more Zats are acquired, and other SG-1 members often sling one, in case someone needs to be subdued, or vaporized. In other episodes, even Teal'C uses "regular" guns, so yeah. In a scenario that is much more squad-based than any real military actions we often have, the group is all equipped. Daniel doesn't duck behind stuff, waiting for the gunfire to stop (after season 3 ); he's got the same gun and gear.

With only Nids using psychic powers to make force fields, it would seem weird to have your carapace-wearing unit run into a fight, and watch as their trench coat-wearing Psyker Asset gets his assets handed to him because he's squishy. One can't rely on the rest of the squad to also double-duty, just to watch that one guy's tail, who they might be hoping gets shot, anyway.
 
I'm not pushing for weird stuff. It just makes sense that if the Psyker is with the Cadians, they'd kit him like a Cadian. All his "attached" status should really do is mean that he might be more likely to move, turn in his gear to the Quartermaster, and get more appropriate gear. If one thing is something he's not trained for, then he doesn't take THAT one. As for the guns, every use of his powers, no matter how important or trivial, is a small chance that he explodes, taking his buddies with him (worst case scenario, but these guys are trained to expect WCS when a Psyker is around; what Emokin did to impress Padme in Star Wars could've gotten the whole squad a date with Daemonettes in 40K), so having a laspistol, to shoot the little dregs, is advised, probably even comforting; if it backfires, a Lord of Change doesn't show up. I would think that, for the most part, the DMun would equip every guy in the squad about equal, minus "this one gets better", because otherwise they are issuing a liability.

For carrying? That's no problem at all. The only issue would be using it, obviously. What carrying guidelines are you referring to? All I can find is "Carrying, lifting, and pushing objects" on pg. 36 of the Only War Core Rulebook, and that tells a very different tale from what you're trying to say.
That said, it would be incredibly useless to haul a staff around in one hand and a lasgun in the other, unless you've also modified the lasgun for that to work. But on the other hand, you could just holster the staff and strap it to your back (or backpack).
I would consider a psyker with a lasgun unorthodox, but certainly not unheard of. The staffs are usually a psy-focus (by fluff; in Only War, this isn't mentioned) but a psy-focus can be almost anything; there is no inherent or clear benefit to carry such a staff in your hands, other than as a last-resort melee weapon.
While I would (personally) probably always go for the staff-and-laspistol approach, there's absolutely no reason, fluff or otherwise, why a psyker wouldn't use a lasgun if he could use it and it was offered to him (unless he has no other psy-focus on him, which should oddly enough never be an issue for Only War psykers).
 
Yes, but they don't actually get it anew. The rules are there to represent fluff, and in this case, the only reason they still have that equipment is because they haven't turned it in. It doesn't mean that there's two sets of Standard Issue Equipment. Logically, they'd end up with their old equipment as well as being issues new Standard Issue Equipment, simply because they are part of a new regiment now, and thus issued that regiment's standard issue equipment, as per standard.
 
Why? That makes no sense at all. Support Specialists are attached to their squads, and squads are part of a regiment. Just because you come from somewhere else or that you are on loan from higher authority, doesn't mean that you don't operate under a given regiment's command structure or supply authority.
Standard gear is issued as a matter of standard, to everyone that is part of a regiment, in order to maintain a given level of operative capabilities, as judged by regiment command or Dpartmento Munitorum authority (because sometimes the regiment just has no choice; congratulations, your advanced recon regiment is now being repurposed into an artillery regiment, turn in all your cameoline cloaks, please!).
Saying that the only thing they would get is stuff they need for missions is ridiculous, because that's the reason anyone gets gear. The regiment doesn't issue gear, standard issue or otherwise, because it's fun. They issue gear, standard or specific, because that's what they think that the squad or regiment overall need to complete their mission(s).
Why would they willingly crippled themselves by not issuing standard gear to people under their command, performing missions in their name, attached to squads trained in your regimental boot camps, out of some misguided idea that "Nah, these guys are on loan from the commissariat, so they don't need silencers on their weapons" or "No way we're supplying the psyker with a gasmask! He's just on loan from the Telepathica, anyway." or "Why would we give the priest a lasgun? He's got his flamer. Since we're an artillery regiment we're not issued weapons-grade promethium, but whatever."
 
Support Specialists are part of the regiment. They just happen to come from somewhere else or have special training that cannot otherwise be acquired. They get their gear and replacement gear not from some vending station unique to each organization in the Imperium, but from the exact same regimental quartermasters as everyone else.

There are a few premises to make the calculations, I'm going to assume the fallowing. 
The shooter is adept with ranged weaponry (BS 40). The shooter spends 1 half action on aiming, otherwise accurate doesn't function and the comparison is void. No extra talents are applied to the equation. The shooting is done within 25 meters, to give both settings close range benefit We're shooting at a good possible target for Incinerate-mode TB 4 and Unnatural Toughness(4) I'll start out with Incinerate as it's the easiest one. 
To-hit = 70 from 40+10(aim)+10(standard attack)+10(close range)
Damage possible is minimum 4(8), maximum 9(13)
50% of the time is 4(8) damage, with damage rolls of 1 to 5. afterwards 6 to 10 has10% each.
Average damage is thus (5*5+6+7+8+9+10)/10 = 6.5
 
30% chance to fail damage
35% chance to do 4 damage
35% chance to do 5-9 damage
Average damage is 4
 
Precision-mode gets heavier on the math due to the difference in damage depending on the DoS.
To-hit = 80 from 40+10(aim)+10(standard attack)+10(close range)+10(accurate)
1 DoS deals 0(4) to 5(13) damage
2 DoS deals 0(5) to 15(23) damage
3 DoS deals 0(6) to 25(33) damage
 
Hit-rolls of 80 to 71 counts as 1DoS
1 DoS is straight forward. damage-rolls of 1 to 5 does no damage, 6 to 10 deals 1 to 5 damage
 
Hit-rolls of 70 to 51 counts as 2 or 3 DoS
2 DoS deals 2D10+3 damage and we're leaving "basic" math and enter probability. The damage possible is 2 to 20. However the probability to get 2 is not the same as 10 or 11. to get 2 we need to roll 1+1, only one possible way. 3 can be both 1+2 and 2+1. The damage rolls that fail to do damage are 2,3,4 and 5. each with their probability of 1/100, 2/100, 3/100 and 4/100. the total probability to roll 5 or less with 2 D10s is 10/100  =1/10
 
Hit-rolls of 50 to 01 counts as 4+ DoS
As with 2D10s but even harsher, 3 D10s can only roll 3 once every 1000 rolls. 4 is rolled 3 out of 1000 and 5  is rolled 6 out of 1000. In the end, only 10/1000 = 1/100 damage rolls deal no damage. 
 
this adds up to
27.5% = 20 + 10*0.5 + 20*1/10 + 50*1/100 % chane to deal 0 damage
5% = 10*0.5 chance to deal 1 to 5 damage
18 % = 20*9/10 chance to deal 1 to 15 damage*
49.5%= 50*99/100 chance to deal 1 to 25 damage**
* statisticly speaking we're expecting 6 in average
** statisticly speaking we're expecting 11 in average
 
The end result is
27.5% chance to fail to do damage
12.9% chance to do 4 or less damage
59.6% chance to do 5-25 damage
Average damage 10.7475

I want to stress that compasses might be rare, considering that there's no guarantee that a planet will have a magnetic field mirroring that of Terra, or even anything remotely close. Thus the Imperial Guard would need something that can be used on multiple worlds, perhaps always pointing at a geographically chosen "North", or perhaps always pointing you flatly back to base.
I honestly have no idea how this would work, and as far as I know, there's no precedence; it just occurred to me as I saw the thread. I might be spouting nonsense, who knows?
If it's a basic solution, compasses might be widely available, but there's also an argument to be made that digital compasses, programmable tools capable of accepting data in order to supply guardsmen with relevant information that is useful (such as a regiment-wide accepted "north" or frame of reference) is exceedingly rare, or at least so rare that only a single person in a squad might receive one.
It is also possible that various regiments have widely varying kinds of solutions to this problem.
That being said, returning more closely to topic, I'd assume that a Set of Basic Tools would be pliers, knife, a multi-tool, a full weapons maintenance kit, etc. I do not think that it would contain a compass or entrenching tool, or at least these are not the things I think of when someone says "a Set of Basic Tools".
I'd say that it would be reasonable to assume that your Sergeant (or whomever you designate) has access to some kind of Compass, yes. At least some kind of very basic Multicompass, if nothing else. Display directions, compass bearings and arguably indicate altitude, but no built-in maps, topographical data, etc.