Hello all, I was looking through the books and the forums on this one and I was wondering if any of them stack? Assuming that they are all rating 6, do any of them work together or only the single highest one? I know this has probly already been asked but I couldn't find it. I thank you for any help.

I would expect that when any armor bonus is compared to cyberware of the character, they don't stack. If you have both, only the highest is applied.

Sorry, I ment to say for reducing falling damage. Each one of them reduces falling by 1 meter per rating.

No reason to be sorry.

However, it doesn't stack. If you have both, only the highest of either applies. Same thing with bone lacing as compared with bone density, or reaction enhancers and wired reflexes.

http://www.shadowrun4.com/resources/faq.shtml

Just checking but not even the Freefall adept power stacks?

Because the power of Mystic Armor stacks with normal armor and cybernetic armor, I would allow the stacking of the Freefall Adept power with other stuff.

I strongly suggest investing in a parachute if you're that worried about falling ^_^

Don't be ashamed of questions, though. It's how we learn. I ask my fair share of questions on here too. Just remember to pass it on and answer questions when you know the answers.

I agree with the others. The jacks won't stack with each other (Just like buying two rating 1 wired reflexes doesn't work, or two rating 4 muscle toners, and so on). But the freefall would work with the jacks, since they are from very different sources. Fluff also supports this as freefall is an ability to actually fall slower, while the jacks operate by absorbing the impact for you.

Wait, back up.

You have hydraulic jacks in your legs.
You then put on power armor, which has external hydraulic jacks.
Each set of hydraulic jacks absorbs a certain amount of kinetic energy when it activates.
Therefor, two separate sets should absorb the sum of their kinetic energy absorptions.

If there is a rule stating they do not stack, please point it out to me, because logic and physics dictate they should stack.

Furthermore, Freefall doesn't state how it operates, but it allows you to ignore fall damage, presumably by slowing your fall or somehow bleeding off the kinetic energy. This should also stack.

~Umidori

I don't think there is a rule that states they don't stack. But I also don't think there is a rule that states you can't get 2 muscle toner wares, or 2 of any other ware. It is one of those things (For the multiple ware thing) that is so assumed you don't even bother mentioning it.

That said, I did think of what you said slightly after I'd posted, but decided to leave it hoping no one else would notice. I figure the main reason would be that it would be difficult to have them work in tandem. Both would require you to make the same motion, and it is questionable if both would be able to operate at the same time, and even if they could, there is a limit to how much you can break the fall.

I mean if you are going from 60m/s to 0m/s over a distance of a foot, there is a limit to how much of that can be absorbed purely by your legs, regardless of what your legs are made of or have in them. Your main body is still mostly going from a very high speed to a very low speed in a very short amount of time. Yeah, I like this argument right here the best.

Lemme run the physics.

G = 9.81 m/s^2
6m + 6m + 6m = 18m

v = final velocity; u = initial velocity; s = displacement (distance); a = uniform acceleration
v^2 = u^2 + 2a * s
v^2 = 0 + 19.62 * 18
v^2 = 353.16
v = 18.78m/s

So when you hit, you're traveling at 18.78 meters per second, 61.62 feet per second, or 42.01 miles per hour. You've also been in the air for less than 2 seconds.

Now, how much that hurts is dependant on your weight. For the sake of sanity and simplicity, we can handwave that away by saying that the jack systems are designed to operate under standard ranges of weights - troll sized jacks will be designed to accomodate average troll weights, for example; armor jack systems take into account the added weight of the armor; stuff like that.

If you don't do that, the rules just don't work. The rules are a linear increase of damage with distance, whereas the amount of force you have to deal with at the end of a fall increases exponentially with distance. The physics just do not match up, and the further you fall the crazier the disparity becomes.

I will admit, if you fall far enough (183.6 m, or 602.35 ft) to be traveling 60 m/s on impact (196.84 ft/s, 134.21 mph), you're screwed no matter what. But that's also reflected in the rules. If you fall 184m - 18m for jacks and Freefall, you still take 85P damage. And that's not even terminal velocity via rules. (Yes, there are rules for terminal velocity. In the Corebook of all places.)

Now, if you really wanna argue semantics, I'm more than happy to calculate exactly how much kinetic energy each jack system can absorb independently via physics and compare it to the handwaved values of ignoring 18m of falling (which would impart more energy) and come up with a house-rule value which adds diminishing returns to the extra systems, but realistically it isn't going to be that big of a difference.

~Umidori

i don't see why any calculations would be needed.

it's quite simple really;

2 jacks will give you twice the distance to decelerate over. i don't know that i would let them stack in power armor purely because if your power armor could stretch far enough to fit your built-in leg jacks, it would probably just put it's own (rating 12) hydraulic jacks in it.

but if you were falling on something that had the same hydraulic jack system which managed to land jacks first, and you also applied your own, i don't see any reason it wouldn't stack. as i said, it simply doubles the distance over which you decelerate, which quite effectively reduces the force further.

(so, for example, if you strapped your feet onto the shoulders of a suit of this armor, and managed to aim the armor so it lands feet down without dropping you flat on your face, then both jack systems would stack).

on a side note, i would be inclined to allow something like hydraulic jack extensions that you could wear that would be designed to use your hydraulic leg jacks to absorb more damage. but it wouldn't be a standard powered armor hydraulic jack system, it would be a specially designed piece of equipment.

In my opinion they can stack - but with a caveat : if you're putting an off-the-rack powered armor with your jacks-equiped legs, they won't work well : different triggers level, don't push exactly in the same direction, different speeds.... which would limit the stackin (a guesstimate would be one third to hone half of the lowest grade system).

Taking full benefit of both systems will require them bo be interfaced and fine-tune to synchronize their action. They can, but just slipping on the armor 'off-the-rack' won't do it. All said, it's basically designed to work with unjacked legs (and the jacked legs aren't designed for external assistance either).

As of the Arsenal Errata 1.3.2, there's no mention for clarification.

As far as I know, doubling up the same kind of equipment doesn't stack the benefits unless the equipment explicitly says otherwise. As a reference, in the SR4a book, it explicitly says bone lacing and bone density are incompatible (IIRC, previous errata said you take the better of the two only; still no stacking), and armor does have explicit rules for stacking as well.

You're failing to account for a few basic principles of physics.

Okay, imagine you only had one leg with a jack system, but you wanted to get twice the benefit by adding to the hydraulics. Would you bolt a second jack system to the bottom of the first? Or would you just take that second jack system and put it on the other leg?

Yes, doubling the compression depth of hydraulics would make them twice as effective. Then again, so would doubling the surface area, which is what you do when you add the hydraulics to your other leg as well. You split the total force by spreading it over twice the area, as opposed to channeling that same force into a system twice as deep. The same concept applies to internal and external jacks - they are "side by side", just like your two legs, rather than stacked on top of each other.


The difference here is that we're talking about combining Cyberware with Armor Enhancements, not Cyberware with Bioware. Would you argue that Strength bonuses on milspec armors don't stack with Cyberware as well?

~Umidori

You can use reaction enhancers with wired reflexes. The rules specifically mention it.

That all said: Umidori makes a great point, which renders the discussion irrelevant in regards to the stacking of jacks:

Just because you now have two identical systems, with identical technical limits, does not mean they can now magically absorb 36 times the amount of impact energy.
At MOST you could argue that two sets rating 6 jacks count as one set of rating 7 jacks, but that's as far as it goes.

In the absence of specifically written rules, we might have to make a judgement call.

- Armor Gyro stabilization doesn't work with a cyberam Gyro or a Gyro harness, because logic fails.
- Armor Strength Enhancement can work with cybernetic enhancements, because your arm can stabilize the armor beyond it's carrying capacity, but that is stretching it already. Personaly, I wouldn't let strength enhancemens stack, either, but that's just personal opinion. It would at least be plausible to have them stack.
- Now for the Hydraulick Jacks: Physics bust that idea. The amount of energy they would need to withstand, if you were to stack their ratings would be insane. Way beyond safe specifications and utterly absurd.

As far as Freefall goes: completely different mechanic. First, it's magic. Second, it decreases falling speed. On those grounds, I would allow it to stack with jacks in my campaign.

Hehe, D2F. I think that Umidori was trying to make the exact opposite conclusion that you drew with what he did. None the less I agree with you like I said earlier. Regardless of how much hydrolic fluid you have in your legs, your body is still going from high speed to low speed in a small amount of time, and there is a limit to how much cool stuff you can have in your legs before it doesn't change how quickly you stop without getting accordion legs.

Strength Enhancements I would say work not because of any particular physics reason or anything, but because the rules spell out 'This strength enhancement works with whatever strength the user has' and then lists some questionable reason as to why. Basically it says "It doesn't matter if you're a weak human or a troll, you can get 3 extra points of strength, no more, from this armor, and you can even go over your augmented max." I think it is the mention of breaking the augmented max that is important, because without augmentations, no metatype has a strength that would allow for breaking of the augmented max without already having augmentations.

Alright I concede then. I still think it's stupid, but if the rules say strength enhancement works, then it works, simple as that.

So we can all agree that Freefall and jacks work in tandem.

I would still argue that the two jack systems in tandem would work as well, but I would be willing to admit you'd probably have diminishing returns. A combined total of 7 seems off to me, but I'd argue 12 is equally off. Perhaps 8 or 9 would be good. I might do the math and calculate the forces just to figure out what kind of dropoff is reasonable. Over relatively short distances, such as 12 - 18 meters, it shouldn't be too big a dip in effectiveness.

That said, because the jacks do not explicitly state they work together, but also do not explicitly state they do not work together, I'd make it a GM call.

~Umidori

if you simple decelerated instantly from 100 m/s to 0 over a distance of 1 millimeter in mid-air rather than against the ground, you would still be just as dead. it isn't about spreading out the force, over an area, it's about how fast you have to decelerate, which is in this case decided by the length of the hydraulic jacks. if the jacks are already slowing you down at the highest rate they safely can, it doesn't matter if they can slow you down faster than that, because as the saying goes it's not the fall (or even hitting the ground) that kills you, it's the rapid deceleration at the end. there is a maximum deceleration beyond which your body cannot safely go, and having the equipment to go beyond that safe point doesn't do the slightest bit of good. on the other hand, there is no maximum distance over which your body can be safely decelerated. so no, i wouldn't put two jacks side by side. slowing you down twice as fast will cause damage. slowing you down over twice the distance at the same rate will leave you unharmed.

Rule of Cool says it all stacks, at least in my games. And not just 'cause I had an Adept/Cyber show up as a nasty NPC to one-up a less extreme character in some short fiction, once.

How's the game gonna break if someone's investing magic and nuyen and Essence all towards something like running and jumping, instead of just being able to punch through a tank, shoot an arrow through a bus, talk a lesbian into giving 'em a bj with ridiculous social dice, or shoot the wings off a fly? If someone wants to be a jump-monkey Parkour type, bounding around the city and not being terrified to jump from a high distance every now and then -- so they can look awesome -- why not? It's likely to break the system much less than other places they could hyperspecialize.

And just when they came to a reasonable, equitable resolution, Critias has to mess it all up with AWESOME!

For the record, I'm totally with Critias.

If you drop from a building, I agree, you are fucked. The problem is, the numbers I crunched are so very much smaller than that.

If you fall 18 m, you only hit at 18.78 m/s. You're in the air for just under two seconds. You are suffering a 42 mph impact with the ground. The forces are much, much smaller than if you hit at 100 m/s.

I'm simply arguing that you are overestimating the force of impact in reasonable drop situations, and underestimating the force absorption capable by the jacks. Yes, the sudden deceleration is what hurts you, but that deceleration is being drawn out by the hydraulics. It works, I'm almost certain. I'll do the numbers this afternoon and share what I find.

~Umidori

One could argue about two times bio muscles level one that act as bio muscle level 2 would.
Or two times dermal armor level one that acts as dermal armor level 2.
And 2 Cyberlimbs DO stack both in Armor and in the extra Box of Damage on your Track you can take.

Just why the Adept would do this is beyond me though.
Get the Free-Fall-Power and the Armor, AND A SUSTAINING FOCUS or what have you with a high level Cat-Fall or Feather-Fall or whatever in it.
Maybe even simply a Levitate Spell that lets him slow down his fall.

Suggestion:
Armor hydraulic jacks and cyber hydraulic legs add up to a combined rating of 6 (the max. that can be done), the Freefall power adds to both (it´s magic).

How do you increase the ratings of the system, in physical terms? Heavier-duty cylinders, that absorb more energy before bottoming out? So if you double the size of the cylinder, it should be the same as putting on a second cylinder of the same size.

Where does that number 18m come from, if you get to stack both jacks at max rating you can combined with freefall you can fall 36m with out damage test(assumin all are rating 6) thats more then a few floors of a building. Add to that someone like my ork falling adept who can throw 30 dice to resist falling damage and you got someone who can on avarage jump down from a 10th floor of a building and take no damage on the fall.

Compared to the magician/adept with levitation, he still is weak ^^
pity that this can't be combined with the ultimate mundane climber somehow.
have him climb up the biggest tallest building he can find and jump down.
Basejumping without a parachute O.o