Perfect Organism's Warhammer 40,000 conversion thread.

[Sam Baughn]

I've converted a few bits and pieces from the Warhammer 40,000 setting in the past, but I thought I'd try and be a bit more ambitious and do a more coherent job, so that the various items and characters match up against each other fairly well.

The source material for the setting is obviously not entirely consistent, so I'm going to try and look at multiple sources. In case there is disagreement on how things work, I'm generally going to favour Forge World background material first, then the Black Library novels (with Dan Abnett and Sandy Mitchell generally being ranked above other authors), then the Fantasy Flight games (Dark Heresy and Rogue Trader), then the background descriptions in the wargame codexes, then the background descriptions from other spin-off games and finally the rules from the wargame.

In some cases, I'll try and present multiple options for how things work. For instance, the descriptions of flamers vary wildly in how they work and how powerful they are. I think it's entirely possible that 'flamer' could just be a generic term in the Imperium for any incendiary weapon which projects a blast or spray suitable for attacking troops dug in to cover at short range and that some such weapons operate on entirely different principles to others.

I'd like to try and stay fairly close to the technology presented in GURPS Ultra-Tech, both because this means I have to do less work in statting things out and because it makes it easier to port things from this setting into others and vice-versa.

[Sam Baughn]

Let's start with something which thankfully has a pretty close equivalent in Ultra-Tech: the humble lasgun.

A lot of quotes here. I don't intend to do this kind of thing for every single item, but lasguns are one of the central technologies of the setting (probably the most common weapon in the galaxy) so I felt that they should really be one of the baselines which everything else is judged against.

Originally Posted by Warhammer 40,000: Wargear (1993)

The lasgun or laser gun is the standard weapon of the Imperial Guard and the most popular weapon among most human forces. It fires an explosive energy blast with a similar effect to a bullet or small shell. A lasgun may not be the most effective weapon in the galaxy, but it is easy to manufacture and maintain and very reliable under even the toughest battlefield conditions. The lasgun is powered by rechargable batteries, but carries a residual supply and can be recharged using it's own solar converters.

Originally Posted by Rogue Trader Core Rulebook (2009)

Produced by the millions on countless forge-worlds, laser or 'las' weapons are by far the most numerous type of weapon in the Imperium as they are the basic tool of the countless soldiers of the Imperial Guard. While somewhat complex to manufacture, their STC template is well known and their extreme ruggedness and ease of use makes them the perfect weapon for the Hammer of the Emperor. Las weapons can be found on almost any planet even outside the Imperium and among many Xenos mercenary tribes.

Las weapons work by emitting short, sharp pulses of laser energy from high capacity fast-discharge generators, with a flash of light and a distinctive snap like the cracking of a whip as the trigger is pulled. Though they are produced in a mutitude of different styles and patterns depending on the home world of manufacture, most use a very common Departmento Munitorium sanctioned power pack. The liquid metal core of the pack stores vast amounts of energy and can be recharged from standard power sources or even via exposure to intense light or heat in a pinch. In emergencies they can even be recharged by placing them in an open fire, though this diminishes the lifespan of the pack and increases it's failure rate.

Originally Posted by The Imperial Infantryman's Uplifting Primer by Matt Ralphs (2007)

The lasgun is made to the same specifications (with a few variations) all over the galaxy. it is the most reliable ranged weapon ever manufactured. It is light, simple to maintain, has a decent range and accuracy and has won many wars since the inception of the Imperial Guard. You can drop it, hit it, use it as a club or submerge it, and it will keep on working (although it is recommended that you do no do any of these things unless absolutely necessary).

Originally Posted by Gaunt's Ghosts: Ghostmaker by Dan Abnett (2000)

Fencer got up to the nest top and raised his lasgun. Five hundred metres ahead, through the smoke and the rubble, he saw the first shapes of the enemy, troopers in heavy, ochre-coloured battledress, advancing in steady ranks.

Fencer began firing. Below Kolea opened up too.

Originally Posted by Chapter Approved (2003)

They had barely got within 500 paces when a horde of fanged and clawed Hormagaunts leaped from the building's upper windows and bounded at them. The Guardsmen obeyed their training and Seargent clay's terse orders; firing short controlled bursts form their lasguns as the Hormaguants closed.

In Fifteen Hours a veteran guardman tells a new recruit that there is no point shooting at orks at 1000 metres as even if he hit, it wouldn't have enough power to kill them.

Later when facing a push from the orks, the guardsmen wait until they are within 300 metres before opening fire with carefully aimed shots (possibly aiming for vital areas to maximise damage).

In Ghostmaker, Larkin kills an enemy commander with a headshot with his long-las. The range is implied to be around 2000 metres.

So, a standard lasgun probably has a 1/2 D range somewhere around 330-550 yards and a long-las may have a maximum range of 2200 yards or more. Even PDF troopers and conscripts seem to think they have a fair chance to hit human-sized targets at 550 yards, so Acc is probably at least 8 and maybe as high as 12.

Originally Posted by Execution Hour by Gordon Rennie (2001)

A las-blast felled the armsman beside Semper. The captain grabbed the man as he fell, intending to drag him into the bay, but then found himself staring into the excavated crater of the man's skull, where the las-shot had blown half his head away.

Originally Posted by Gaunt's Ghosts: In Remembrance by Dan Abnett (2001)

But Mktag had been shot. Right there in front of me. He fell at my feet, his heels drumming the ground, his hands spasming. A tiny plume of smoke spiraled up from the little black hole a las-round had made in his forehead. There was no blood. The shot had cauterised the entry wound and it didn't have enough power to exit his skull. Its heat and force had been expended getting into his cranium and incinerating his brain.

It was quite simply the most awful thing I have ever seen. His body thrashing, trying to live, the brain extinguished. I think if there had been more blood, more obvious physical damage, I could have coped better.

But it was just such a tiny hole.

Originally Posted by Gaunt's Ghosts: Ghostmaker by Dan Abnett (2000)

An enemy warrior loomed ahead of him and Mkoll blasted with one of his pistols, taking the head clean off.

Some rather different descriptions of the effects of las shots to human heads, but all lethal. This tells us that most las weapons can probably do at least a couple of dice of damage (enough to reliably cause a death check on a hit to the skull) and probably more like five dice (enough to cause instant death to a normal human on a hit to the skull).

Originally Posted by Gaunt's Ghosts: Ghostmaker by Dan Abnett (2000)

He shot him point blank and then rose, cutting the knees off the next foe who advanced with a double spit of las-fire from his guns.

Originally Posted by Gaunt's Ghosts: Honour Guard by Dan Abnett (2001)

He didn't feel the las-round hit his shin, but his leg went dead and he fell, tumbling over and over in the drifts.

A las shot to a limb usually cripples it, but doesn't always result in dismemberment. That suggests around three to four dice of damage.

Originally Posted by Gaunt's Ghosts: Necropolis by Dan Abnett (2000)

A las-round punctured Captain Olin Fencer's body at the hip and exited through his opposite shoulder. As he fell, weeping, he clicked his lasgun to autofire and sprayed his massing killers with laser rounds.

His hand was still squeezing the trigger when the pack ran out.

By then, he was already dead.

Originally Posted by Warhammer 40,000 Compendium (1989)

As the stones pattered to the ground, a Deathlight flashed the stunted bushes itno flame. Tarok sprang up and fired at the Brannath who had just given away his position. The man fell forward out of the bushes with a fist-wide, smoking hole punched through his body from front to back. Strange, thought Tarok, that there is no blood.

A single las shot to an unarmoured human torso will often be fatal. That implies somewhere between five and eight dice of damage.

Originally Posted by Gaunt's Ghosts: Necropolis by Dan Abnett (2000)

An enemy round took off his hand at the wrist and Corbec scooped up the autocannon and fired it himself. Genx, his stump instantly cauterised by the las-fire, got up without comment and began to feed his colonel's weapon.

Larkin took his targets as they came, blowing off heads or blowing out chests with the powerful kick of his sniper gun. The las-fire of the normal weapons was superhot but lacked stopping power. Larkin blanched as men beside him hit enemy troops who kept going despite precise hits which had passed through them cleanly. Only Larkin's sniper gun and Corbec's autocannon were actually dropping the foe first time so they wouldn't get up again.

It's not that unusual to survive a lasgun shot to the torso either (at least in the short term). That imples that five to seven dice is probably around the upper end of damage (enough to cause a single death check for most people). This passage was probably inspired by accounts of people failing to drop dead after being hit with 5.56 rounds, so you could infer that a lasgun does similar damage to a modern assault rifle, although that's fairly tenuous logic.

Originally Posted by Gaunt's Ghosts: Necropolis by Dan Abnett (2000)

The las-hit had cauterised the wound, so there was precious little blood, but the heat had melted the larynx and the windpipe into a gristly knot and Feygor was suffocating.

Not quite sure how that would translate into GURPS rules - possibly a more urgent version of a Mortal Wound. Again, this is probably enough damage to force a death check, so five to seven dice would be fairly appropriate.

Overall I'd say that five dice of damage would be a fair approximation of what we see from the novels. The various different types of las weapon available and the possibility of variable power settings give us a bit of 'wiggle room' to account for some shots seeming to be significantly more damaging than others.

[Sam Baughn]

Originally Posted by 13th Legion by Gav Thorpe (2000)

I pull off my helmet and look at it, still a bit dazed from the hit. There's a charred gouge just where my right ear would be, almost burnt through. I poke at it with my finger and I'm shocked when my fingertip passes straight through. The las-bolt had been within the thickness of a piece of parchment from actually getting through!"

Originally Posted by The Imperial Infantryman's Uplifting Primer by Matt Ralphs (2007)

The helmet you were issued with will provide you with the best protection avaialble. It is lightweight (about 2 kg) and extremely durable. It is fully capable of deflecting las-rounds, slower velocity solid shot and shrapnel. It is built using several layers of carbon-fibre and contains the earpiece of the vox-link. When activated this powerful receiver will pick up orders and information from the squad or command centre vox-com.

A guardsman's helmet is (just about) capable of stopping a las shot. At best, it's probably equivalent to a TL 10 Light Infantry Helmet (DR 24), so a (2) armour divisor might be a bit much if we go with the 5d damage. Maybe (some) guard helmets include an anti-laser ablative layer, either as an outer cover or a liner or possibly they are simply significantly thicker than the ones in Ultra-Tech. Either option would help bring the weight up from the 3 lbs in ultra tech to the 4.4 lbs. in the IUP.

Originally Posted by Gaunt's Ghosts: Ghostmaker by Dan Abnett (2000)

The laser burst punched through the top of the bandit's bowl-helmet, presented as it was by his head-down appraoch. The shot probably passed down through his skull, his neck, and his torso, following the line of his spinal column, Merrt thought, as the figure dropped stone dead in a crumpled pile.

This (presumably less sophisticated) helmet doesn't seem to offer much protection from a lasgun shot.

Originally Posted by Gaunt's Ghosts: Ghostmaker by Dan Abnett (2000)

Men were still coming off the ramp-end above, falling on those Ghosts now coming up from below. A boot had hit him. The man it belonged to was inverted in the water behind him, panicking, dying. Caffran kicked away, trying to rise and not breathe in to ease his emptied, screaming lungs. He saw men explode into the grey, dreamy world from above, fighting the water as they hit and sank. But that at least told him the surface was only a few metres away.

The man who had kicked him on his way down had become entangled with another by the slings of their lasguns. One of them fired his lasgun in desperation, twice, three times. The water boiled around each slicing minnow of orange light. Caffran's ears throbbed as they heard the fizzing reportt of the underwater shots. One of the las rounds punctured a drifting corpse nearby; another punctured through the leg of a desperate swimmer next to Caffran. Blood fogged the water.

Originally Posted by Gaunt's Ghosts: Ghostmaker by Dan Abnett (2000)

Behind him, las-rounds punched up out of the water into the fog as other unfortunates lost their grip on everyting but their triggers as they drowned.

Originally Posted by Eye of Terror by Barrington J. Bayley (1999)

Steam bubbled all along the length of the laser beam as it hissed through the water. But it failed to reach Aegelica. Instead, it struck a fish, nearly a yard long, which at that moment had glided between them. The fish exploded as the water in its body turned to steam. Fragments of flesh, skin, and bone drifted to the sea bed.

Some las weapons can evidently fire through water to some extent. This implies that they are either field-jacketed or use the blue-green option (somewhat contradicted by the mention of 'orange light', but that's a fairly minor issue).

Ammunition capacity varies depending on source, but 40-60 shots from a single power pack seems to be about average, with a few sources going as low as 25 shots per pack (Imperial Armour vol. 5) or as high as 150 shots per pack (Munitorium Manual). The Ultra Tech laser carbine using Superscience Power Cells gets 140 shots per pack, dropping to 70 if we assume that they are blue-green lasers or use hot-shots as standard (or if 40k power cells simply don't have the capacity that Ultra-Tech ones do).

So, I think it's fair to say that Warhammer 40,000 lasguns are overall very close to GURPS Ultra-Tech laser carbines.

[Sam Baughn]

If lasguns are equivalent to laser carbines, that gives us a bit of a basis for statting the other kinds of las weapons.

A laspistol is simply a Heavy Laser Pistol.

A long-las might be a dinosaur laser, a laser rifle or simple a fine quality laser carbine with some accessories. It doesn't look like long-las are especially standardised, with some specifically being noted as variants of other lasguns, so I guess all of those can work. Snipers with long-las are often shown using 'hot shot' power packs which seem to work a little differently to what GURPS calls 'hot shots' - they use a specific type of power pack for high power shots and these often only get one or two shots per pack.

A hellgun is similar to a lasgun, but a little more powerful, with significantly better armour penetration and using a backpack power pack. A rainbow laser rifle seems like a good fit.

A multi-laser is a bit more problematic. It's a powerful, rapid firing laser weapon which can chop through unarmoured troops easily and damage light vehicles. A gatling laser could work, although its rate of fire is rather low - possibly several gatling lasers mounted together would be a better fit - it does only seem to appear as a vehicle weapon, which suggests that it is fairly heavy.

Finally, we have the lascannon. This is an anti-tank (or sometimes anti-monster) gun, capable of punching through pretty much any armour in the setting. It's a large weapon, usually vehicle mounted. It is sometimes seem carried by marines (unusually large and strong super soldiers) in power armour (battlesuits) and by guard heavy weapons teams (two men with a tripod or carriage mounted support weapon - although the tripod may have anti-grav suspensors or something in the case of the lascannon which looks way too large for two men to carry) though, so it probably doesn't weigh more than a few hundred pounds.

Unfortunately, there is a distinct lack of beam weapons in Ultra-Tech capable of destroying a tank and weighing less than several tons. The rainbow strike laser using hot-shots and aiming at chinks in armour can just about get through DR 1000, but it isn't going to be causing much damage. Maybe 40k tanks are't all that tough, or possibly those high-power power cells used in long-las are also used to give lascannons a boost.

[Sam Baughn]

Basic solid projectile weapons are fairly straightforward: the better ones are similar to the TL 9 weapons in Ultra-Tech, less sophisticated ones would be eqivalent to various lower tech guns (TL 7 for most 'stub guns', down to maybe TL 4 for some of the really crude stuff).

Specifically:

Autoguns are mostly equivalent to the 7mm Assault Carbine. Heavy autoguns like the Agripinaa or Armageddon patterns would be Storm Rifles.

Autopistols are generally similar to the 10mm machine pistol.

Heavy handguns like the Scipio pattern naval pistol might be equivalent to the 15mm magnum pistol.

A heavy stubber is probably equivalent to a storm chaingun.

Shotguns are pretty much just shotguns.

An autocannon might be similar to a 15mm heavy chaingun, possibly with the ETC option. The term 'autocannon' seems to be extremely widely applied though, so there is probably a lot of variation.

An assault cannon could be a conventional minigun with the ETC option, or it could be a Gauss minigun. Again, this term seems to be widely applied (and sometimes confused with heavy stubbers, autocannons and heavy autoguns) so it's quite possible that both weapons could be used with the same name by different forces.

Specialist ammunition seems to be fairly rare in smaller calibre weapons. APEX seems to be mostly reserved for bolters, with autocannons firing either proximity fused HE or APHC. Assault cannons have some kind of armour piercing round - probably APEP, given their performance in some sources. Shotguns get a variety of explosive, multiple projectile and solid slug options but most smallarms seem to be restricted to simple solid shot.

[Flynn]

I am absolutely loving this, please do continue!
Thoughts on Bolters and Auto canons?

[Sam Baughn]

Bolters are large calibre firearms distinguished by the fact that they fire 'rocket-propelled ammunition' or 'small missiles', usually with an explosive warhead.

Stricly speaking, that makes them equivalent to UT Gyrocs but the actual described behaviour and use of bolters doesn't seem consistent with weapons which work best at ranges of ten yards or more - they are the favoured weapon of troops who participate in close assaults, boarding actions and point blank combat. This suggests to me that at least some 'bolt' weapons get most of their velocity before the projectile leaves the barrel and the rocket booster (if present at all) merely serves to extend the range or somehow increase accuracy.

The weapons which seem to suit the effects of bolters we see in the novels and artwork are probably ETC or Gauss shotguns loaded with APEX ammunition. They also come in 18.5mm, which is fairly close to the 0.75" calibre sometimes given for boltguns.

Again, I think it's a good bet that there are actually quite a lot of fairly different weapons used in the Imperium which get classed under the 'bolt' category. A Gauss CAW would be a good match for a space marine boltgun, while a couple of Gyroc LSWs would probably be better for the pintle-mounted stormbolter on an Imperial Guard tank.

Some of the specialist bolter ammunition corresponds fairly well with stuff in UT. Standard bolts are APEX, Kraken rounds are APEP, Storm rounds are HE... although other stuff is less clear. Inferno bolts could be thermobaric (but could equally well be armour piercing incendiary), Tempest solts are probably EMP, Vengance could possibly be some kind of experimental HEDP with a chance of exploding on a malfunction, no idea what Hellfire would be.

[Azinctus]

Originally Posted by Perfect Organism

Forge World background material first, then the Black Library novels (with Dan Abnett and Sandy Mitchell generally being ranked above other authors), then the Fantasy Flight games (Dark Heresy and Rogue Trader), then the background descriptions in the wargame codexes, then the background descriptions from other spin-off games and finally the rules from the wargame.

I'm very interested in this project. I am thinking about doing something similar (or just using your stuff). I would have taken the wargame as the primary source, particularly the fluff from Warhammer 40,000 Rogue Trader (the first edition of the wargame). But then I've never read any of the novels, so maybe I've got the whole thing backwards.

Originally Posted by Perfect Organism

Lascannon [...] can just about get through DR 1000, but it isn't going to be causing much damage. Maybe 40k tanks are't all that tough, or possibly those high-power power cells used in long-las are also used to give lascannons a boost.

I wouldn't have thought the tanks are any tougher than WWII tanks. And the Lascannon and Krak Missile are simply bazookas. If the tanks are future-super-tanks the Tyranids and Terminator Armour are going to have to be future-super-tough to offer any resistance at all to those weapons. That won't work because the same armour is supposed to be slightly vulnerable to lasguns and bolt guns. Meanwhile Imperial Guard flak armour offers some slight protection against boltguns and not a great deal of protection against lasguns.

My rough guess is that Flak armour is DR10-15, Power Armour is DR30-40, Terminator Armour DR100 and Heavy Tanks DR150-200.

However with a Lasgun as a Laser Carbine all that has to be increased....

Well I'm not too clear on how I would do it. Tell us more about how you are going to set up 40k. What are your ballpark figures for armour? Will Imperial Guard be able to kill Marines with concentrated Lasgun fire?

[Tectuctitlay]

I've got a Warhammer 40 K to GURPS thing I started, but will in all likelihood never finish (I've decided to go in a differant direction with it). If there's any interest, I'd be happy to upload what I do have on my site.

[Sam Baughn]

It's probably worth considering that someone in the Imperium is more likely to identify an item by the function it serves and/or the degree to which it's manufacture and maintenance require permission from the Adeptus Mechanicus. A shotgun and a bolter might both be conventional smoothbore weapons capable of firing a variety of different ammunition, but if one can be manufactured and maintained by a common gunsmith and the other requires the attentions of an enginseer, they are likely to have very different social and legal status despite being essentially fairly similar.

Likewise, a conventional flamethrower and a plasma flamer are totally different in how they operate, but if they look similar, get used in a similar role and have a similar legal status, then they are likely to be considered essentially the same thing by many members of imperial society.

Anyway, moving on to some more weapons.

Melta weapons are powerful anti-tank beam weapons, notable for their extremely short range. Again, we have the problem that Ultra-Tech weapons tend to be not well suited to an anti-tank role, in this case with the added complication that most of them also have extremely long range.

A few candidate present themselves:

Conversion beams certainally do enough damage. Unfortunately, they also have much too good range and there isn't a model which is conveniently the right size for a standard melta-gun (somewhere around 12-20 lbs.). They are also TL 12^, which is a fair bit higher than the TL 10 laser carbine or TL 11 rainbow lasers and melta weapons aren't really considered amazing technology.

Fusion guns do a fair bit of damage, but probably not enough to get through tank armour and again, they have too much range.

Plasma Flamers have a range which looks about right and their description matches some versions of how melta weapons work (although there are a bewildering number of different descriptions, none of which make very much sense). The downside is that they really don't have the power needed to get therough tank armour.

Screamers are short ranged and could eventually cut through almost anything, but they unfortunately don't come in the size range I was looking for and most descripions of melta weapons have them blasting the target apart near instantly, not slowly melting through it over several minutes. They also don't do burning damage, while melta weapons apparently have a significant thermal effect.

X-Ray lasers have a short range (in atmosphere at least), decent penetration (although fairly low damage) and conveniently come in dinosaur (melta gun) and semi-portable (multi-melta) versions. Maybe the damage can be increased through the use of super-charged power cells, as I mentioned for lascannons.