Ultra-Tech Gun Noodlings: How to Figure Bulk and Magazine Length

Sup fam. Got some quick but tasty nuggets for you today.

First off I've come up with a way of figuring a weapons bulk that gets good results. This is NOT official by any means but it seems to work. It is a bit fiddly though. 

First you're gonna have to fi
gure to values:

Bul and Buw.

Bul is based on the weapons length in millimeters and can be figured as:

6 × LOG₁₀(Wl/305) + 2

Wl is the weapons length is millimeters. 

Buw is based on the weapons weight (unloaded if mounted) in pounds and can be figured as:

2 × LOG₁₀(Ww) + 2

Ww is based on the weapons weight (unloaded if mounted) in pounds. 

The weapons actual Bulk then can be figured by taking the average of Bul and Buw and then slapping a negative signto it. 

For example: A FAMAS G2 is 757mm long and weighs 8.4lbs. This gives us a Bul of 6 × LOG₁₀(757/305) + 2 or 4.4 and a Buw of 2 × LOG₁₀(8.4) + 2or 3.8. This gives a Bulk of (4.4 + 3.8)/2 or -4. While there are no stats for a FAMAS in any official book, HANS was kind enough to provide the forum with a write up and sure enough it's bulk is -4. 

 And while we're here, might as well throw in a quick way to estimate a magazine length, just so you can get an idea if your magazine modification is practical (and should let you know you're not going to see a huge increase in the number of caseless rounds a standard magazine can hold).

Magazine height can be estimated as number of rounds × rounds actual diameter (this might differ from the listed one, a 5.56 NATO round is actually ~5.7mm) × the polymer/plastic magazine type weight modifier for a given magazine type found on High-Tech p.155 under Extended Magazines. Multiply this value 0.7 for curved magazines like most military rifles use.Adjust the height by +/-10% as needed.

Why am I getting some casting couch energy form this pic?

For Example: a 20 round magazine for a FN Five SeveN is about 126mm (~5 in.) tall. The actual diameter for the round is 5.7mm and used a high-density magazine which has a polymer/plastic weight modifier of 1.1. This gives us a height of 20 × 5.7 × 1.1 or 125.4mm (4.9 in.). Close enough for government work.

So why am I thinking of gun stats all of a sudden? Well, I know, bad question. When am I NOT thinking of gun stats after all. Well I may or may not be working on expanding the kinetic side of Ultra-Tech firepower in my next few posts. I do hope to get some stuff out soon but I am also working on some non blog related projects so  maybe that might be more on the soonish side of things but they'll get there.

Ultra-Tech Ultra Quickie: Experimental Melee Rules Part II: Power Weapons

Ok, looks like my last post is getting some traction. I'm in inspired mode so let's keep this content train ah-chuggin!

Power Weapons (TL 10)
Power weapons use some form of force field to increase their impact force, be it gravitational, electromagnetic, or some other energy herein unknown to modern science.

Power weapons let off a glow that can provide some light but also give their users position away when activated. They will act as a light source that is bright enough to give a modifier of LOG₁₅(damage adds) -3 or if you want more details they will be as bright as a light with a lux of 5 × LOG(damage adds). See GURPS Powers: Enhanced Senses p. 13 for more information on how light levels translates into light level modifiers. 

For weapons that do cutting, impaling, or piercing damage they increase the weapons Armor Divisor by one step (to a max of 10) and add TL -3 points of damage adds, crushing attacks only get the damage adds. +13CF.

They also worsen the odds breaking for  a non-force weapon on a parry by 1.

This can be increased to TL -2 for +1 CF, TL -1 for +4 CF,  TL for +9 CF, or TL +1 for +19 CF.  
 

Power weapons need a power source to function, usually power cells.

A standard C cell will power a power weapon for TLp/divide by weapons weight in seconds. TLp is 75 at TL 10, 150 at TL 11, 225 at TL 12.

A +1 power weapon halves this duration, a +2 one cuts it by a 1/3 , a +3 one cuts it by  1/5, and  +4 one cuts it by 1/8th.
 

Legal class worsens by 1 to a max of LC 2.

DR Steps

Find your weapons base Armor Divisor (AD) on the below table and for each step your modifiers adds, move down one step on the table. For example if you have a base AD of 2 and have one step worth of AD modifiers you will move down one step and your weapons now has a AD of 3.

 

Step AD

0 1

1 2

2 3

3 5

 

Ultra-Tech Ultra Quickie: Experimental Melee Rules Part I: Updated Vibrobalde Rules

Update: Formatting issue fixed. I guess you just can't copy your text over from Google Docs and need to paste it in a simple editing tool like notepad first >.>. Like Google owns both Docs and Blogger.... you'd think they'd be integrated... but then again Google is utter trash trash. 

Update 2 Electric Boogaloo: Fixed a typo. The cost factor for upgrading damage to TL -3 was wrong (have no idea why I had it at +3) and has been changed to the correct +9 CF.

Another quick one since the inspiration hit me out of nowhere. Here's a experimental reworking of the rules for Vibroblades found in Ultra-Tech p. 164 that cleans it up a bit and makes it more modular. If you like this I'll  make other posts covering this stuff and update other options such as Super Fine and Hyper Dense and even add some new options.

Vibro/High Frequency Blade (TL 9)
Only available to weapons that do cutting, impaling, and or piercing damage (though optimized for cutting weapons). Vibro and High Frequency (or HF) technology are two means to reach the same end; to vibrate the blade at ultra high frequencies to better slice through objects. Vibro weapons use ultrasonic waves while HF weapons use high powered alternating current but otherwise their effects are identical (though HF tech has uses outside of just making blades effectively sharper).  

A downside is the vibrations make an audible humming sound when activated. Make a hearing based Per roll to detect. See below to figure out the base range that someone can hear the weapon but in most cases the sound level will be that of a normal conversation for detection purposes.

To find out the exact range you can hear a vibro/HF weapon first find out its decibel rating.

Decibels Rating equals 20 × LOG( weapon weight in pounds × TLm×Em × 10). TLm is 2 at TL 9, 1 at TL 10, 0.5 at TL 11 and 0.25 at TL 12. Em is 2 if you upgrade to TL -5, 3 at TL -4, 5 at TL -3, 8 at TL -2.

Then take the Decibel Rating and look it up on the Hearing Distance table in High-Tech p. 158 or Loudness Levels in GURPS Powers: Enhanced Senses p. 21.

Characters with Ultra-Hearing can detect a vibro/HF weapon at 10× its normal range.

If your character wouldn't know what a vibro or HF blade is then a further IQ roll is needed to figure out why you hear a humming noise. On a failure you write it off as a ringing in your ear or something similar.

If a character has either enhanced time sense or perception at 20+, they can simply see the weapon oscillate.

For weapons that do cutting, impaling, or piercing damage, when the vibro/HF function is turned on  they increase the weapons Armor Divisor by one step (to a max of 10)  and only for cutting damage they add TL -6 points of damage adds.  When turned off the weapon does its base damage. +9 CF.

This can be increased to TL -5 for an additional  +1 CF, TL -4 for +4 CF,  TL -3 for +9 CF, or TL -2  for +19 CF.

Vibro/High Frequency Blades need a power source to function, usually power cells.

A standard C cell will power a Vibro/High Frequency Blade for TLp/divide by weapons weight in seconds. TLp is 37.5 at TL 9, 300 at TL 10, 600 at TL 11, 900 at TL 12.

A +1 vibro/HF weapon halves this duration, a +2 one cuts it by a 1/3 , a +3 one cuts it by  1/5, and  +4 one cuts it by 1/8th.

Legal class worsens by 1 to a max of LC 2.

 

DR Steps

Find your weapons base Armor Divisor (AD) on the below table and for each step your modifiers adds, move down one step on the table. For example if you have a base AD of 2 and have one step worth of AD modifiers you will move down one step and your weapons now has a AD of 3.

 

Step AD

0 1

1 2

2 3

3 5

4 10 

 

 

 

High-Tech/Ultra-Tech Ultra Quickie: Have a seat while I blow you off your feet.

Blast Resistant Seating

Blast effects from mines, IED (Improvised Explosive Device, i.e. home made boom-booms) and near hits from artillery rounds have been found to have a much greater effect the people inside a vehicle even if the blast fails to penetrate the vehicles armor then GURPS assumes. 

Well, they're having a blast.

This is largely because advancements in blast protection has lead to situations where a vehicle survives where it would of been blown to scrap in the past leading to the crew being killed anyways. So now we're finding that even if the blast can be mitigated enough to prevent complete destruction of the vehicles, the shock waves can still be transmitted through the hull into the spine of the poor crew doing nasty, nasty, neurological damage. 

So if you're ok with some extra crunch and want more gritty realism, use the following rule:

 

Blast Damage Through Armor

If a blast fails to penetrate a vehicles DR, use the rules for HESH rounds found on GURPS High-Tech pg. 170 but change the cutting damage to crushing. If using the Lasting and Permanent Injury rules from GURPS Martial Arts pg. 138 (and if you're going gritty you should be heh!) use the Skull Wounds Table. 

So there you go, another way for you, the GM, to make your party dead, dead, dead!

...

Oh right... wait... *slaps forehead* We're trying NOT to kill our PC's.... what was a I thinking?! 

Thankfully after they figured out that concussive blast were turning our troops brains into scrambled eggs they quickly figured things out. If you isolate the chairs they're sitting on from the hull by putting them on a shock absorber style damping system you can can reduce the G forces being exerted on the crew member by a factor greater then 10, turning an impulse that would crush internal organs and slam your brain into the top of your skull into something that might break some ribs and bruise you badly instead. Still sucks buuuut given the alternative I know which I would choose. 

Soooo, you might be wondering, how good are these things? Take a good look at the photo below.

This Styker flipped over and rolled several times after it got hit and an IED. Despite the level of damage you see, no one was killed or even severely injured. So pretty damn good it seems. 

Mobius Protective Systems Advanced Protection System

So as a counter to the Blast Damage through Armor rules, might want to equip your combat vehicles with some of these things. So here's the rules.

Blast Resistant Seating

Blast Resistant Seat (TL 8). These seats isolate the person sitting in them from the frame of the vehicle they are in and uses shock absorber like dampeners to help dissipate the energy from shock waves and impacts. Provides DR 15 vs collision damage (see Whiplash and Collisions Basic, pg. 432) and shocks damage from none penetrating blast damage. Increase DR to 20 at TL 9, 30 at TL 10, and TL 50 at TL 11+. $1,500, 44 lbs. 

If you are adding the seats to an already stated vehicle such as a TL 8 Humvee (GURPS High-Tech pg. 242) or a TL 9 Wheeled ATV (GURPS Ultra-Tech pg. 225), add +24 lbs and +$1,300 per seat to the vehicles states. This will come out it's normal payload limits.

Ultra-Tech Ultra Quickie: Frag Out!

Quick update to get my creative ball rolling again.

In GURPS 4th edition an explosives fragmentation damage has been tied to the diameter of the warhead that carries it, that is the warheads diameter (in millimeters)/20. Now this works good enough in most cases but some warheads are designed to create an enhanced or heavier fragmentation effect. Below I cover two warhead options to get more fragmentation bang for your buck. See this post for even more Ultra-Tech warhead options.

High Explosive Enhanced Fragmentation Warhead (HEEF) (TL 9) 
This warhead uses either a thicker or denser case to create an enhanced fragmentation effect with greater penetration and wounding potential. Due to the stronger case, the warheads blast effect is reduced.

 Blast effect damage is figured as the square root (warhead weight)×19.8. Divide the product by 3.5 to get dice of damage. Damage is crushing explosive.

 Fragmentation damage is figured  as Warhead Diameter (in millimeters)/12 in dice of damage. Damage is cutting fragmentation damage.

Add +1 per die to the crushing explosive damage at TL10-12. This warhead is only available for 15mm or larger. Double normal cost.

HEEF projectiles, with the exception of hand grenades, that are built at TL 9 or higher can incorporate a programmable fuse that can be set for either impact or, if the target is at least 40 yards away or farther, for proximity detonation  see Ultra-Tech pg. 154. Grenades and satchel charges with HEEF warheads inflict the damage shown below. When set for impact detonation,guns and launchers with HEEF warheads inflict their normal piercing damage with a (0.5) armor divisor, plus a follow-up attack causing the damage shown below.

HEEF Table
Warhead           Damage
15mm              1d-2 cr ex [1d+1]
18.5mm           1d-1 cr ex [1d+2]
25mm              1d cr ex    [2d]
30mm              1d+1 cr ex [2d+2]
40mm              2d cr ex     [3d+1]
64mm              4d cr ex     [5d+1]
100mm            8d cr ex     [8d+1]      
130mm            12d cr ex  [11d-1]
160mm            8d×2 cr ex [6d×2]
400mm            4d×16 cr ex [5d×7]



Continuous Rod Warhead (TL 9) 
This is a special type of High Explosive Enhanced Fragmentation Warhead. A Continuous Rod Warhead surrounds the explosives with a bundle of metal rectangular  rods welded to one another at the top and bottom in an alternating pattern.

When the warhead goes off, the bundle of rods are propelled outward in an expanding ring, unfolding like a circular accordion gate.This effect not only greatly increases the warheads lethality against thin skinned targets, though it is less effective against thicker skinned or armored targets. Up until the ring finally breaks apart it is far more likely to hit targets within its effective range  then standard fragments (with hit probability dropping at a rate of 1/R rather than 1/R² as for conventional fragments).

Even after the ring breaks the rods are still dangerous and have the hit probability of a normal fragmentation warhead.

While effective, Continuous Rod Warheads are more complicated and expensive to build then normal fragmentation warheads. They are also more effective with larger warheads (the first production warhead was the early TL 7 710mm RIM-8 Talos with a 30 yard effective range!).

A Continuous Rod Warhead has similar effects to a High Explosive Enhanced Fragmentation Warhead only the fragments have an armor divisor of (0.5) and fragmentation has both  a primary and a secondary threat range. In the primary threat range the chance of scoring a hit is increased.

The fragments still hit with a skill of 15 but penalties do to range to the target are ignored. Primary threat range is fragment dice of damage × 0.5 yards.

 In the secondary threat range use the normal fragmentation rules with the exception that you trace the range from the end of the primary threat range when figuring range penalties- not the center of the blast.

Blast effect damage is figured as the square root (warhead weight)×19.8. Divide the product by 3.5 to get dice of damage. Damage is crushing explosive.

Fragmentation damage is figured  as Warhead Diameter (in millimeters)/12 in dice of damage. Damage is cutting fragmentation damage with a (0.5) armor divisor.

Add +1 per die to the crushing explosive damage at TL10-12. This warhead is only available for mm 64mm or larger. Five times normal cost.


Continuous Rod projectiles are always set for proximity detonation- see Ultra-Tech pg. 154.


Continuous Rod Warhead Table
Warhead         Damage                      Effective/Secondary
64mm              4d cr ex     [5d+1]        3 yrd./26 yrd.
100mm            8d cr ex     [8d+1]        4 yrd./41 yrd.            
130mm            12d cr ex  [11d-1]        5 yrd./54 yrd.
160mm            8d×2 cr ex [6d×2]        6 yrd./60 yrd.
400mm            4d×16 cr ex [5d×7]      18 yrd./175 yrd.
        

Ultra-Tech Ultra-Quickie: How Much Explosives Are In a Ultra-Tech Warhead?

As any GM can account, sometimes PC's can get a little too clever for their britches and think outside the box.

For example: Let's say after disarming a bomb that was going to take out the presidents personal shuttle one of your players decides they're going to remove its explosive filler so they can repurpose it later.

Great! Smart lil bugger.... Now you just gotta figure out how much boom-boom is in this dang thing. Sure you can just pull a number out of your butt buuuut then you gotta hope you remember why you picked this number later if you have to do this again and hope no of your players are an "expert" on explosives and go, "Actually!"

Well good thing there is a way to figure how much explosives are in the warheads listed in Ultra-Tech!

First you just have to figure out how much a given warhead weighs and if you have read this blog post you should already know how to do this but to make your life easier I'll just give your the formula again.

Warhead weight = Warhead diameter (in mm)³ × 0.000002.

See Warheads R' Us for how I came up with this, my more observant readers might notice that this will give you same results as stating up a small warhead in GURPS Vehicles 3rd ed which in turn is the standard that Transhuman Space used for it's warheads (which in turn was a major influence on the 4th ed version of Ultra-Tech).

Now that you have how much the whole warhead weighs, we can now separate the explosive filler from the casing, fuse and other necessary components. 

To do that just take the warheads weight and multiply if by 0.78 annnnd boom! The product is the weight of the actual boomy part of the thing. Of course in real life this would vary based on what kind of warhead it was, how it was fused and so on this does at lest give you a good rule of thumb that is consistent and lines up with GURPS RAW.

Hmmmm?

Oh right.... you want to know how I came up with this, silly me. 

Well, if you open up your Basic Set to pg. 415 you'll see there's handy little formula to figure how much damage a given amount of explosives do. You just needed to know the weight and the explosives REF (relative effectiveness factor, or how powerful it is compared to the same amount of TNT).

Now let's look at a 100mm warhead which weighs 2lbs and a TL 9 HE warhead does 6d×5 cr ex.

To give a base line let's look at what 2lbs of TL 9 HE would do (I'll save you the crunch on this one but it's safe to say that TL 9 military explosives in Ultra-Tech are Plastex B/ Octanitrocubane) with a REF of 4).

Using the listed formula 2lbs of HE would do 6d × square Root of (2lbs × 4 × REF(4)) or 6d×5.56, which would normally be rounded to 6 but that would throw off the results. 

Now if we compare how much damage a 100mm warhead does compared to 2lbs of just HE that the warhead does only about 88% of the damage. Now since damage is based on the square root of the weight of the explosives, just convert that 88% to a decimal and square it which gives us a weight modifier of about 0.78. 

So this means that a 2lbs warhead should have 2lbs × 0.78 or 1.56lbs worth of explosives. So if I'm wright, if we plug 1.56lbs into the explosives damage formula we should get 6×5 and look at that, the formula gives us 6d×4.99 dice worth of damage. Bam! 

Oh, and another use for this knowledge is now you can swap out the plastex B and try out different types of explosives. For example, if we decided that we wanted that 100mm warhead filled with Nanoscale Thermite (Ultra-Tech, Too Pyramid 3/51 Tech and Toys III) we now knows that it can hold 1.6lbs worth which will burn for eight seconds and cost $320. 

I know this wasn't too big of a post, especially with how long I've been out of the game but rest assure I do have some more post in the works, two that give you more warheads to play should be done soon, with as well doing some major research into Robotech: The Next Generation/The Sentinels mecha and weapons so I should have more Ultra-Tech fun for you guys soonish.