D&D General Doomsday Weapons?

[Coroc]

An idea hit me as I was trying to go to sleep last night, the "Black Door", a portal to the Plane of Vacuum so big it sucks a world's atmosphere away, destroying all life on the planet. Have you thought of a spell or device that could wreck a planet? What are your Armageddon devices?

My party had one last session. It was epic. They had the ashen staff assembled in Tovag Baragu, all three parts. An universal portal key. An artifact which could amplify a spell (Rain of colorless fire) to destroy two nations.

They were asked by Ilkbens spirit (encased inside the crystal of al Anfar, part of the staff) what he could do for them. They correctly asked for Iuz portal to the abyss in Dorakaa to be closed.
The party could witness that mentally.

After that Istus the god of fate released Ilkben from his prison into the afterlife and sealed the artifact into the stone center of Tovag Baragu.

The Tovag Baragu gate system (looks a bit like a kind of Stonehenge) was surrounded by thousands of Centaurs who guard this place and were alerted by foreknowledge of their shamans and the beam of light in its center.

During the assembling of the staff there were emanations from all the portals in Tovag Baragu.

Theoretically the party had an artifact in their hands with which they could have destroyed Oerth, had they asked for it.

 

[Bohandas]

I had a couple ideas. Although none that I've actually used in campaigns.

1.) The Ad-Infinitum Cannon- A device that would siphon conceptual infinity out of the Grand Abyss (the huge literally bottomless pit at the center of the first layer of the Abyss) and focus it into an infinitely powerful energy beam capable of firing between planes and utterly destroying anything that it's aimed at. Basically a combination of Starkiller Base from Star Wars 7 and the Ad-Infinitum Siphons from the game Afterlife. The campaign would focus on the varying factions vying for control of it as its being built and the varying factions trying to stop it from being built; this last category would include various demons who want to stop it due to its potential to end all the fighting.

2.) Proper, movie style zombies that create spawn, carry deadly disease, can take ridiculous amounts of punishment, and sometimes suddenly move fast for a moment instead of their usual slow gait.

3.) A flesh colossus with a sibriex for a head

4.) Tungsten rods dropped from a spelljamming vessel in the upper atmosphere

5.) An SCP-Society-esque cult that steals all the magic stuff and in doing so plunges the world into conditions reminiscent of the real medieval period

6.) A fleet of seven spelljamming ships, each bearing a figurehead in the shape of a dragon, collectively rigged with an apparatus that duplicates the means by which Tiamat stole Krynn from its original crystal sphere.

7.) The Temple of Elemental Evil's bottom floor reimagined as some kind of evil reverse version of the temple from The Fifth Element that is capable of firing a death ray when activated by the correct ritual

I'll post more when I'm less tired and more coherent

 

[jgsugden]

#1.) In my world the idea of Entripy is represented by the Far Realm crashing into the Prime Existence. Demons were created from Devils when the Far Realm first made contact with the Hells. Aberrations first started appearing across the planes at the same time. The world will end, eventually, when the Far Realm entirely collapses into the rest of my cosmology.

#2.) Demon infestations. Tried and true, I've ended a number of campaign worlds (at least temporarily) when a bad guy managed to open a huge number of permanent portals to the Abyss all at once. Sometimes they are accompanied by portals to the Eemental Planes as well.

#3.) Drive the Gods off. A common these in many campaign world histories is a time when the Gods are cut off or abandon the Prime Material Plane residents. This results in an instantaneus reshuffling of the power structure, and usually a massive war or two to end all wars.

#4.) Science. In my world there are 5 types of magic - Arcane, Divine, Natural, Psionic and 'Elemental'. Elemental is not fireballs and such - it is instead science and supernatural forces. It follows very different rules than the other magic sources and can be used for anything science can cook up. For example, nukes, disease, or mass drivers.

 

[Bitbrain]

I don't think that's a liquid.

Well, it is technically possible. One positron and an antiproton and you’d have anti-hydrogen...

EDIT
Assuming of course, that you can prevent them from smashing into each other.

 

[Coroc]

Wait what. I thought they change than from 3E. Here is what I wrote of 3E and updated for something in 2008.
***

Decanter of endless water.
Ok let see the time to fill various things with the decanter.
For an oval swimming pool the calculation is Len * width * avg depth * 5.9 to find the number gallons an oval pool holds. For a rectangle swimming pool the calculation is Len * width * avg depth * 7.5 to find the number of gallons a rectangle pool holds. I got the calculation from a swimming pool site.
A 16 by 32 foot pool with an 8.5 deep end and 3 shallow end, holds about 22,080 gals so my parents’ pool holds a lot. The decanter has the rate of 30 gallons per round = 300 a minute = 18,000 an hour = 432,000 gallons a day, and 157,680,000 gallons a year. Then it would take 1.226 hours or 74 minutes to fill the pool at my parents’ house. Dad will be happy.
For 10 by 10 by 10 room it would take 25 minutes to fill. The orc will have time to eat his pie and brush his teeth before he starts to get worried. For a 20 by 20 by 20 room it would take 3.33 hours (3 hours 20 minutes) or just enough to enjoy one of Lord of Rings before you drown.
If want to fill the Empire State building 424 * 424 * 1250 * 7.5 (this max volume not true) 3901 + days. 10 years 251 days (I could not find where the dimensions of the breaks were)
Looking at the sample dungeon in 1e and 3e DMG and fill it to depth of one foot. The sample dungeon is 577.5 squares making 5775 * 5775 * 7.5 * 1 foot deep = 250,129,687.5 gallons or 579 days. This does not take in account the depth of the various stair ways and if the water was able to enter all parts of dungeon.
My house is 1300 square feet. So 1300 * 10 (I don’t have ten foot ceilings) * 7.5 = 97,500 gal it will take 5.4166 hours or 5 hours and 25 minutes. So if I late going home for lunch my house would be over flowing from the two chimneys. Hope the cats remember to hold their breath.
The old joke about Englishman, Scotsman and Irishman with a wall around England. England is 93,000 square miles. 93,000 * 5280 * 100 (foot wall) * 7.5 (water) = 368,280,000,000 gallons = 2,335 years 225 days. So if the decanter of endless water starting filling England on the stroke of midnight in the year 2000 you would have to the year 4334 November 24. 11/24/4334.
The Earth’s total surface area is 197,000,000 square miles. 197,000,000 * 5280 * 7.5 would result in 7,801,200,000,000 gallons. 49,474 years,323 days and 8 hours.

How much water would give to town’s people besiege? A person needs one liter of water a day to replace water loss by normal activities but needs 2.5 quarts to maintain health but this includes water contain in food.(American Water Works Association 25 facts about water). It was hard to find an exact minimum of water usage per day which did not include modern appliances. I am going to go with one gallon to include bathing, cooking, or activities. So one decanter could supply the needs of any fort. If you use the one hundred gallons of water per person per day (this include modern showers, dishwasher, and washer) a larger village can live a modern life if the population is under five thousand and the orcs are at the gates. So the only major problems would be spellcasters dispelling the decanter, weather in the winter freezing the bottle up, and vandals.

A fire engine can put out up one thousand gallons of water a minute on the water cannon. To get down three hundred gallons a minute you have to go to the “Neptune” 1837 fire engine in Toledo Ohio museum.

Decanter of Endless Water: If the stopper is removed from this ordinary-looking flask and a command word spoken, an amount of fresh or salt water pours out. Separate command words determine the type as well as the volume and velocity.
“Stream” pours out 1 gallon per round.
“Fountain” produces a 5-foot-long stream at 5 gallons per round.
“Geyser” produces a 20-foot-long, 30-foot-long 1-foot-wide stream at 30 gallons per round.
The geyser effect causes considerable back pressure, requiring the holder to make a DC 12 Strength check to avoid being knocked down. The force of the geyser deals 1d4 points of damage but can only affect one target per round. The command word must be spoken to stop it.

Oh goody. New stuff from the army.
The 3,000-gallon onion tank is a highly mobile, easily transportable, manually inflatable, collapsible fabric water tank. The tank is 23 by 28 by 42 inches and weighs 130 pounds packaged. The tank is 56 by 148 by 94 inches and weighs 24,020 pounds filled with water (Figure D-1). From fm 10-52-1 appendix d.
You got your water for the day for 3,000. Call it 30 minutes setup time. Fill time is 10 minutes on geyser. A five man team can rig a support beam so two or more men can hold the geyser. But this a little too big.

In the field mess we had a few collapsible fabric drums which carried 55 gallons when full iirc
It was basically 3 six foot long poles, a metal plate with holes for the poles and chain in center. A od green canvas bag with a dust cover and one metal rim with 3 chains connecting to the center. And the center was clipped into chain above. It took 3 minutes to setup well more if did by the regs digging footing holes for the posts, and laying down peddles to keep the mud down. Call it 10 pds when empty. Fill time is about 6 minutes on stream. Under 2 on fountain. Call it 10 minutes total setup time. Break down time is less especially if empty.

http://www.globalsecurity.org/military/library/policy/army/fm/10-52/Ch2.htm

Speaking of bathing you don’t shower but bathe in your pot helmet or a bucket. So call it a gallon of water each of bathing and you don’t have to bathe each night. But if you need a shower canvas bag with shower head. Call it six poles each 8 feet long. 3 for shower head, 3 for curtain.

So basically your daddy is an orc living in a 10x10x10 Swimming pool on the roof of the empire state building or did I get lost somewhere in your post?

So technically you are a halforc?

 

[Weiley31]

PC 4. So I blew up the planet? How many xp do it get?"

250 XP.

 

[Umbran]

Well, it is technically possible. One positron and an antiproton and you’d have anti-hydrogen...

EDIT
Assuming of course, that you can prevent them from smashing into each other.

A positron and an anti-proton are no more likely to smash together than an electron and a proton. Anti-hydrogen is just as stable as hydrogen.

 

[jgsugden]

A positron and an anti-proton are no more likely to smash together than an electron and a proton. Anti-hydrogen is just as stable as hydrogen.

Yeah, I heard that before. "Carla is a lot like her sister... just as stable and fun. Not a pyromaniac sadist with temper problems. Nope."

 

[Bohandas]

A positron and an anti-proton are no more likely to smash together than an electron and a proton. Anti-hydrogen is just as stable as hydrogen.

He might have meant it you can keep it from smashing into a normal hydrogen atom

 

[Umbran]

Yeah, I heard that before. "Carla is a lot like her sister... just as stable and fun. Not a pyromaniac sadist with temper problems. Nope."

If you leave Carla alone, she's fine. Shove her into an environment where literally everyone is her polar opposite and totally against her, sure, she'll blow up. But you would too, in equivalent circumstances.