Here is the game situation. A fifty ton metal gate is about to slam onto a stone wall. Two suits of incredibly well constructed (made by the finest dwarf smiths) half plate armor, one enhanted to +1, are placed on the stone wall to prevent the portcullis from falling all the way.
When the 50 ton gate slams on the the two suits of half-plate in the middle acting as a wedge six inches in width would they crumple or turn into a huge fragmentation grenade?
As I ruled the latter I am having second thoughts. Having worked only a short time in a metal fatigue lab, I notice when subject to huge forces metal fails spectacularly.
The deeper question is am I a DM that always wants to make it hard on the players?
This is part #1 in my series - Unusual game Situations - How would you rule? Taken from real events on the boards.
it seems to me that without anything inside of the armor to help it hold shape that it would just crumple. Since its open at each end then the energy produced by the collison would just be expeled through the neck and body openeings. 50 tons wouldnt even leave 6 inches of room. Id think it would crumple it damn near flat. a 4"x4" chunk of wood or anything solid in nature wouldve been a better choice.
I think crushed as well. Although you could certainly justifiably do a bit of shrapnel damage to those nearby for dramatic purposes (and given just how many separate bits of metal make up a suit of 1/2 plate) - say 2d6, Ref save for 1/2? (1d6 per suit).
I think that according to RAW in order to damage a magic armour or weapons you need at least as great an enhancement bonus as that of the armour to be damaged. So I hope you've deployed a +1 portcullis.
Actually, thinking about that, if you *did* enchant a portcullis to +1 would that make it immune to battering rams or siege engines that weren't similarly enhanced?
How much room was between the plate and the edge of the collision? If they were far enough inward, I imagine it wouldn't matter how they broke.
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Okay, I've just gotta say, a 50 ton gate?! That better have been described appropriately, because that's a ridiculously large and heavy gate. I mean really, we're talking one that weighs as much as twenty five mid-sized cars. Are they on another plane or something? Because that's really a bigger gate than I'd expect to see anwhere on an earth-like planet.
If it is indeed that heavy, I agree with the decision, but damn, 50 tons?!
So, this is a question of how magical armor fails when under extreme stress. You can examine this a lot of ways, but probably the easiest way is to ask what happens if you slam a 50 ton object down on existing materials.
For virtually any metallic object the answer is well known. The forces would deform the metal, in this case crushing it. For virtually any crystalline object (glass, diamond, stone) it would shatter, sending fragments in all directions. However, the full energy of the gate doesn't get transferred into the shattering object so even a crystalline object wouldn't be likely to explode like a fragmentation grenade.
But it's not clear what "magical armor" is. Perhaps magical armor is stronger because the magic has bound up the armor in some sort of contained force field. If so then it would be plausible that crushing the armor could release that magical energy in an explosion, sort of like the old "retributive strike" that staves could do.
But you have to be careful, because if that's what happens when magical armor is "broken" then it's going to explode if it gets sundered while you are wearing it.
Sundering armor is very rare in my games. Maybe once every year or so in real life time. As a GM I tend not to use techniques that take stuff away from the party, and as a player I've never really played with a sunder build. So very rare.
If this is how you want it to work in your games though, I would make that very clear to the players up front.
I would say a bit of both? I could imagine the heat generated from deforming the metal so drastically and so quickly would cause it it flash fuse, maybe even splashing some liquid metal around. It would be a finer spray then shrapnel, but the heat would make up for that. Also, as Stiehl9s mentioned, it would probably be completely flat.
I would say a bit of both? I could imagine the heat generated from deforming the metal so drastically and so quickly would cause it it flash fuse, maybe even splashing some liquid metal around. It would be a finer spray then shrapnel, but the heat would make up for that. Also, as Stiehl9s mentioned, it would probably be completely flat.
Not that real world physics applies in fantasy worlds, but even a 50 ton gate crashing down on metal would not cause it to flash into liquid metal.
Many, many, many metal items are created by putting metal into 50 ton presses to stamp them. Such presses are almost exactly the same thing from a sudden force standpoint as dropping a fifty ton gate on them. That's a standard way of shaping metal.
If you want metal to flash into a liquid, you're going to have to hit it with something like a meteorite.
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Incredibly well-constructed armor does not produce shrapnel when hit with an unbelievably strong attack. It directs the energy of the impact to select places which bend out of shape without putting the vitals of the wearer at risk.
Anything less is good cause for the customer (or rather his inheritors) to sue the dwarf smiths for selling faulty goods. And we all know how much dwarves love being sued for the shoddy quality of their vaunted products (ie, not at all).
Thanks for the quick responses. I agree the armor should not have exploded, but crushed more. I probably ruled incorrectly. As the gate was iron ore at half the density of iron they did know it was massively heavy.
One half foot thick with 900 square feet of surface area. 450 pounds per cubic foot (from wikipedia-density of iron) times 450 cubic feet = about 200,000 pounds = 100 tons for iron ---> 50 tons for the iron ore.
The wisdom of the boards prevails. I will make this right.
Just for fun.
Assuming gravity to be earth normal, or about 10 m/s^2.
50 tons = 50*2000 lbs. = 10^5 lbs. = 10^5 lbs./(2.2 lbs./1 kg) =45454.5455 kg (mass of the gate)
Force = mass*acceleration
Force = 45454.5455 kg * 10.0 m/s^2
Force = 4.55*10^5 Newtons
The ceiling was 30 feet up, I believe, let's just call it 9 meters.
Velocity = sqrt(2*10.0*9)
Velocity = 13.4164079 m/s
Energy = mass * (velocity)^2
Energy = 45454.5455 kg * 13.4164079 m/s
Energy = 8181818.19 Joules
or a little over 8 megajoules. About a quarter of the energy used in the USN's railgun.
...
Holy crap that's a lot of energy.
I think it is indisputable that the armor may as well not have been there for all the effect they would have had on the gate. They would have been sliced like paper, and not hindered the closing of the gate in the least. It is probably good physics that some shrapnel would have flown around, to demonstrate for yourself, just hack a thin piece of wood in half with an axe.
On a game level, I probably would have left out the shrapnel part, despite it being quite likely physically, only because the pc's made the terrible error of having over 1000g worth of armor destroyed in their attempt to keep the gate open. Just seems they hurt themselves enough with their poor decision even without shrapnel damage.
Holy crap that's a lot of energy.
It is.
Though, you exaggerated it a tad. Unless my physics fails me, kinetic energy was calculated as per E = 1/2m*v^2.
So, you'd get some 4 megajoules.
(By the way, simply calculating the potential energy of the raised gate as W = m*g*h might have been a bit... easier)
SCNR
I guess we could say the gate following generated enough energy to summon a diety, which was needed to save the other players from a massive trap.
I like the slicing balsa wood with an axe analogy. I think the wood does splinter.
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The PRD answers the question rather succinctly and ignores silly physics.
Damaging Magic Items
A magic item doesn't need to make a saving throw unless it is unattended, it is specifically targeted by the effect, or its wielder rolls a natural 1 on his save. Magic items should always get a saving throw against spells that might deal damage to them—even against attacks from which a nonmagical item would normally get no chance to save. Magic items use the same saving throw bonus for all saves, no matter what the type (Fortitude, Reflex, or Will). A magic item's saving throw bonus equals 2 + 1/2 its caster level (rounded down). The only exceptions to this are intelligent magic items, which make Will saves based on their own Wisdom scores.Magic items, unless otherwise noted, take damage as nonmagical items of the same sort. A damaged magic item continues to function, but if it is destroyed, all its magical power is lost. Magic items that take damage in excess of half their total hit points, but not more than their total hit points, gain the broken condition, and might not function properly.
and
Hardness: Each object has hardness—a number that represents how well it resists damage. When an object is damaged, subtract its hardness from the damage. Only damage in excess of its hardness is deducted from the object's hit points (see Table: Common Armor, Weapon, and Shield Hardness and Hit Points, Table: Substance Hardness and Hit Points, and Table: Object Hardness and Hit Points).
FYI, Adamantine has a hardness of 20.
and
Hit Points: An object's hit point total depends on what it is made of and how big it is (see Table: Common Armor, Weapon, and Shield Hardness and Hit Points, Table: Substance Hardness and Hit Points, and Table: Object Hardness and Hit Points). Objects that take damage equal to or greater than half their total hit points gain the broken condition (see Conditions). When an object's hit points reach 0, it's ruined.
Very large objects have separate hit point totals for different sections.
and
Magic Armor, Shields, and Weapons: Each +1 of enhancement bonus adds 2 to the hardness of armor, a weapon, or a shield, and +10 to the item's hit points.
TL;DR
+1 Adamantine Armor full plate would have max Hardness 22, and maybe at most 80HP....maybe 90.
50 ton gate would crush it flat and render it RUINED.
and finally this:
Saving Throws: Nonmagical, unattended items never make saving throws. They are considered to have failed their saving throws, so they are always fully affected by spells and other attacks that allow saving throws to resist or negate. An item attended by a character (being grasped, touched, or worn) makes saving throws as the character (that is, using the character's saving throw bonus).
Magic items always get saving throws. A magic item's Fortitude, Reflex, and Will save bonuses are equal to 2 + half its caster level. An attended magic item either makes saving throws as its owner or uses its own saving throw bonus, whichever is better.
I would give it a saving throw. Caster Level required to make armor +1 is 5. means a saving throw of 4, max.
Roll that 4 or less please, and if it fails, its toast.
Thats how I would roll...but then I'm all pimp like that.