On the other hand, we also need to ensure that burst or auto fire do not "break" the game by becoming too powerful.

That's why we have weapon balance. It isn't about the rules of single fire/burst fire/auto fire, but the weapons that use them.

This is entirely backwards, in my opinion. The weapons should be designed to function within the combat system, not the combat system built around the weapons that exist. Your cake thing makes no sense, and I'm not sure you've thought through what having autoguns inflict 2d10+8 would do to the rest of the system.

My point is that each of the rates of fire should have a reason to be used. Full auto might be the best choice at point blank range, but at 3x normal range? You're going to want a precise shot or you're not going to hit anything. The rules should provide a framework that give players meaningful choices to make in combat, not just, "Well I'll full auto at him again because that's always the way to go." That'd be like fighters full attacking in 3e, which was boring and unfun.

I don't think the problem with combat lies in the damage of each weapon but instead in TB and Pen. To me, the rule set doesn't balance TB, Pen, AP, and Damage very well together or at least in all situations and I haven't even begun to talk about force fields. Force Fields are just one more thing to unbalance the combat system. It's not that I don't want to have to deal with all of these factors but it would be nice if they all worked smoothly as they should. I'm not quite sure what the proper fix for this issue is but it certainly needs to be fixed.

Here are the reasons for messing with single shot weapons.

Realism: recoil exists as a thing, and people trained with weapons don't go full auto for a reason. There's an advantage gained in accuracy to taking a single shot or controlled burst.

Gameplay: auto weapons are automatically better than any similar single shot weapon. Trying to balance them in terms of damage output always puts single shot weapons behind or leads to weird situations like a pistol shot to the head not killing anyone that quickly.

Game design: your options here are to buff something or penalize something. It's always better to increase things rather than add penalties, or to increase difficulty. The system in DH can't increase difficulty without penalty (this make me tempted to write a post about the philosophy behind the d100 system). So, you're left with having to buff things, lest you make a game more about restrictions than freedom.

Short interjection:

I wouldn't start argueing recoil - aside from it being difficult to gauge in sci-fi guns (we already have very capable recoil compensation mechanisms today ), we would have many cases where it'd just feel weird should it be a real issue, either because of the user (power armour?) or the gun (las weapons?). And that's before we consider that such penalties would have to apply to Single Shot weapons as well if used with certain Talents.

As far as increasing difficulty in d100 is concerned, I have to say that the current "DoS = hits" concept is a rather clever way of doing exactly that - without a penalty.

I guess I will have to inject a little "real world" fieldcraft here. Full auto weapons are NOT always superior in combat. Any trained soldier will tell you that given an untrained shooter, An individual is generally less likely to be hit by full auto spray and pray then they are by a well aimed shot from a rifle. IRL warfare fully automatic weapons came into their own when fired at massed groups of enemy combatants (IE polish cavalrymen in WWI). This is why the Soviet army were the first issue fully automatic weapons to their soldiers in WWII; Not that they would hit what they were aiming at but that with an entire company laying fire downrange they would hit SOMETHING! In the BC/OW rules this is fairly accurately modeled with the single, Semi and full auto fire modifiers. A Machine gun fired at an individual at long range has a VERY good chance of missing altogether! If that same machine gun is fired at a horde at range then the size modifiers make it very likely that it will hit something and the DOS from being full auto make it likely to do more damage. Soldiers today will generally take single aimed shots at long range and revert to full auto only in CQB (Close quarters battle) situations. Within the OW framework this makes sense since at close range the "short range" And "point blank" modifiers make for some fairly instagib results especially in the hands of an elite stormtrooper or some such (whose bs will tend to be somewhat higher.) Basically, two bullets (or more) are NOT always better than one. Snipers have a much higher kill percentage than standard infantry for good reason! When a soldier lets fly on full auto most of the rounds miss. There are firing techniques that can somewhat mitigate this but this would essentially translate to a higher BS score. Additionally, we should remember that a good portion of fully automatic fire on the battlefield is actually "Suppression fire" which is again fairly accurately modeled within the rules.

I believe the majority of small arms ammunition expenditure can be attributed to suppression fire, even - at least nowadays. I recall reading a report on the ratio of shots fired vs confirmed kills in one of the recent conflicts (either Iraq or Afghanistan), and if one were to actually try and calculate an accuracy rating from it, they'd surely end up with a very warped figure.

Anyways, the thing is that we're kinda forgetting about the Aim action here, for I would say that an unaimed single shot has no justification to have a higher chance of hitting something than burst fire, as the latter at least features multiple chances of a "quick shot" actually hitting something. Which is probably why, in addition to the psychological effect, higher RoF firing modes are still popular in CQB, where proper aim isn't always an option due to how fast things can happen. This is very different from ranged engagements over hundreds of meters, where troops may have the opportunity to take several seconds to line up their shots.

Now, the question is should we really come up with a system that punishes burst and full auto at long rate whilst still making it the obvious choice in CQB, or should we continue with a simplified mechanic that makes no difference between the ranges? Do we even want this level of realism in games, or are we leaning towards a middle ground between sim and movie-like? Each of these options has their own advantages and disadvantages. But whatever we end up with, it should be maintained with all consequence.

I don't think the problem with combat lies in the damage of each weapon but instead in TB and Pen...

My experience is that damage/TB/Pen values mostly work very well at lower Ranks (with some notable exceptions, namely underpowered Bolguns and Plasma Guns). The system just doesn't 'scale up' as well as I would like...

I'd agree with Lynata. What effect are we going for?

Personally, I'd like a system that feels realistic, because to me, the WH40k universe is a gritty place where battles work mostly realistically. Yes, there are aliens and supermen in power armour, but for a regular human, it all works as you would expect in our world.

As such, I feel that there can't be 'balance' between the firing modes, unless circumstances are taken into account.

Purely by the numbers, Full-Auto will and must be the best. That's why guns can fire fully automatically. Most of the time you should be using Suppressive Fire to keep the enemy from firing at you and your buddys, which ends up 'wasting' a lot of ammo, but if you're taking aim at another human, then you should shred him with Full-Auto. However, thanks to recoil, you won't hit with every bullet.
Semi-Auto tries to compromise: Extra effectiveness through multiple bullets, but less shots to try and increase the chances of hitting with each one.
Single-Shot is something you should only be doing if you're confident that it will be enough, or if you need to save ammo.

Of course, implementing a system like this runs the risk of ending up like DH1, where anything that isn't Full-Auto is not worth it.
To avoid this, ammo and perhaps stealth or collateral damage, must be a concern. Technically, this is already in the game, but with the low RoFs of most guns, it doesn't fulfill the role of Full-Auto limiter well enough.
Additionally, Full-Auto should hit with proportionally fewer shots than Semi-Auto.

This still leaves Single-Shot as the red-headed stepchild. I don't want to buff all Single-Shot weapons to the point where they are ridiculously better than comparable weapons, but they need to have some advantage, some niche that other guns don't.

Maybe Accurate can only be a quality of Single-Shot weapons. Maybe they have markedly higher Pen values (the Long-Las goes in the right direction with this). Maybe a Full-Auto weapon just doesn't take long-range scopes, so that you can't compensate for range penalties entirely. ¹
Something, anyway, that makes them a valid choice in any situation and the best choice in some situations. This would still make Full-Auto the go-to option if you've got the ammo, while not punishing Single-Shot or Semi-Auto.

¹ Incidentally, I think the range penalties are far too small. Like many numbers in this game, they are confined to a small range, making all the weapons 'samey' and providing little room for niches.

40k is a setting where you have people stomping around in solid plates of powered armour, and firing lasers at each other. I think sacrificing a little realism in the gun simulation department can't hurt things too much.

I don't see the need to draft up overly complicated mechanics to differentiate the different firing modes. Sure, it makes for a much more realistic simulation of how guns work, but the 40k system really doesn't need to have more nuanced rules piled onto it.

Honestly I think just tweaking the damage values is a fine way to make single-shot oriented weapons appealing. Make it so that weapons like handcannons provide more reliable, consistent damage, whereas high RoF weapons like autopistols are more of a risk; they have the potential to do far more damage, but at the same time, the potential to do pretty much jack **** due to being soaked up by armour.

This doesn't solve the issue of the single shot mode on high RoF weapons being relatively unappealing, but I've never viewed that as a particularly major issue. If you want to be opting for more reliable single shots, you should just get a weapon tailored to that playstyle.

I don't think that adding recoil is particularly complicated, but okay, let's leave that out.

I like the idea of single shot weapons having a much more consistent damage output than other weapons. It would be one way of defining them and giving them their proper niche, as opposed to other weapons.

I also agree that using a Full-Auto gun on any other setting must not necessarily be a good idea unless you're almost out of ammo.

I have already proposed a solution to this problem: increase damage drastically on all weapons. When your bog-standard autogun can dish out 2D10+8 damage/shot then the question quickly changes from "How?" to "How well?' .

Well ... the game becoming a "BANG! You're dead" kind of deadly experience would be one solution, because overkill wouldn't be very efficient. However, whilst I like a game being deadly, I also like the idea of my character surviving at least 2-3 hits from a "bog-standard autogun", after armour reduction.

Hey, I've been playing with such a high-damage system for nearly 6 session and I have nor problem with it. Yeah, you should drop the usual WH40k RPG combat mentality and play with your brain turned on, but it isn't really a bad thing.

And for the people who wants a buff for Single Fire: I'm still curious what do you think about weapons that do have something to compensate their Single Fire only nature. If you buff Single Fire just because the Autgun then you will also buff the Single Fire for the Multi-Melta, the Lascannon and even the friggin' Lance Blaster (because that weapon is not crazy-broken OP enough...).

As I've said, I don't particularly want to buff Single Shot. I want all options that the game gives me to be meaningful and really despise false choices in games.

So these guns that you've mentioned shouldn't get more powerful, because they fulfill a niche, they have an important role to play. Other Single Shot weapons don't, and that's one of the issues. Apart from meant-to-be-weaker weapons like the Las-Lock, all guns should have a reason to exist/be used by the PCs. Same goes for fire modes: Why can my gun even fire Single Shot if that's just plain worse than not doing so?

Or, making an example:
For the Lascannon, Pen and Damage give it a valid role against tanks.
For the Lasgun? It has ammo capacity on its side and is more reliable than Autoguns, which aren't strong arguments in its favor. Unless we start properly tracking ammo, which I think would be a great way to balance Full-Auto anyway.

Does that satisfy some of your curiosity, AtoMaki?

Unless we start properly tracking ammo, which I think would be a great way to balance Full-Auto anyway.

Properly tracking ammo has always been an assumption in every 40kRPG, as far as I can tell. Why would ammo acquisitions/purchases be a thing otherwise?

Does that satisfy some of your curiosity, AtoMaki?

Yeah, but I wasn't referring to you .

Personally, I'm not against sh*tty weapons. It is not like you always use the weapon you want anyway, and I like options that only exist to troll the PCs .

Unless we start properly tracking ammo, which I think would be a great way to balance Full-Auto anyway.

Properly tracking ammo has always been an assumption in every 40kRPG, as far as I can tell. Why would ammo acquisitions/purchases be a thing otherwise?

Agreed. I got confused by someone who claimed that it would be additional bookkeeping.

What I meant to say is that I think the RoFs are often so low that even properly tracked ammo hardly matters.

It just breaks immersion for me when an MG has a full-auto fire rate of 48 rounds per minute... Obviously, that way it's never necessary to reload, either.

And AtoMaki: Fair enough

Unless we start properly tracking ammo, which I think would be a great way to balance Full-Auto anyway.

Properly tracking ammo has always been an assumption in every 40kRPG, as far as I can tell. Why would ammo acquisitions/purchases be a thing otherwise?

Agreed. I got confused by someone who claimed that it would be additional bookkeeping.

What I meant to say is that I think the RoFs are often so low that even properly tracked ammo hardly matters.

It just breaks immersion for me when an MG has a full-auto fire rate of 48 rounds per minute... Obviously, that way it's never necessary to reload, either.

And AtoMaki: Fair enough

That was me, and I was referring to your suggestion of adding Recoil stat to weapons and making rate of fire variable (up to X bullets, instead of just X bullets).

This thread is pretty terrible, by the way. I hope FFG can see that.

FFG seem to operate in two states; blatantly ignoring player feedback, or blindly implementing it.

Just hope it's the former this time?

Maybe the best way to make single shot more viable is to just decrease magazine size across the board. If you're actually worried about running out of ammo you might have a reason to watch your rate of fire.

A better idea I've heard kicked around is making the single shot action automatically a called shot.

Reloading isn't interesting. Nailing a dude in the face with a precision bullet is interesting.

A better idea I've heard kicked around is making the single shot action automatically a called shot.

Then look at the Failed Beta and behold: Singe Fire is the Called Shot !

Something else to keep in mind for the realism crowd is that fully automatic weapons work on the principle that hitting someone with a single bullet is the goal, because getting shot once incapacitates the vast majority of people. It's not like the movies where people shrug off dozens of bullets, and the few times it happens in real life are notable for their rarity. The principle of fully automatic weapons in dark heresy RAW is to hit someone with as many bullets as possible, because it takes a lot of bullets to incapacitate someone. And, as has been mentioned, since the point of full auto is to actually hit a target just once in reality, it's only actually useful when the disadvantages of recoil or distance don't overshadow it.

So yeah, comparing the reality of automatic weapons to how they work in dark heresy is a fools errand because of the lethality of the system.

Then look at the Failed Beta and behold: Singe Fire is the Called Shot !

Something worth adapting from the failed beta, imo - although I would limit this to point blank and short range.

PS: I take it my idea with the "Burst and Autofire = only 1 damage roll + bonus" was not well received?

@ Lynata: I like it enough to do some research, see if it might work. I think it depends largely on the injury mechanic being used. I may get back to you in a PM.

A better idea I've heard kicked around is making the single shot action automatically a called shot.

Reloading isn't interesting. Nailing a dude in the face with a precision bullet is interesting.

Actually, now that I think about it, this is a great idea.

I can't see a called shot for every single fire shot working in a universal way. It doesn't make sense that firing a hand cannon over a wall without without looking just to keep an enemy at bay would be classified as a called shot. The same goes for firing a single fire gun on the run without the necessary talents to do so.