Best idea ever!

[Kel_Arath]

Get a Bag of Holding IV, fill it with the biggest rocks that will fit in it. Then get 2 10ft sections of rope. Then get a spring, a tube that the bag fits in, and 2 big stakes. Tie the ropes to the stakes, then to the lip of the bag, then compress the spring (big spring) in the tube, then place bag in tube. Launch.
Now the bag flies 10ft then gets turned inside out and 1500lbs. of boulder go flying out!
Obviously you have to more carefully tie the ropes and stuff but it would still rock! (get it? rock?) Also maybe four ropes so it doesn't just spin around at the end...
Ooh, one more thing, how big of an object can you fit in the bag? Vertically obviously doesn't matter, but how big is too big to fit in the opening?

[Lord Tataraus]

Get a Bag of Holding IV, fill it with the biggest rocks that will fit in it. Then get 2 10ft sections of rope. Then get a spring, a tube that the bag fits in, and 2 big stakes. Tie the ropes to the stakes, then to the lip of the bag, then compress the spring (big spring) in the tube, then place bag in tube. Launch.
Now the bag flies 10ft then gets turned inside out and 1500lbs. of boulder go flying out!
Obviously you have to more carefully tie the ropes and stuff but it would still rock! (get it? rock?) Also maybe four ropes so it doesn't just spin around at the end...
Ooh, one more thing, how big of an object can you fit in the bag? Vertically obviously doesn't matter, but how big is too big to fit in the opening?

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Why? You want to fling rocks? Dude, its called catapult or trebuchet, and the actually work as well as being less expensive. They might not throw as much but it will be loads more accurate and effective. This thing will just scatter 1500lbs of rocks if it even does that.

[Viscount Einstrauss]

Nah, there's loads better things to put in there then rocks. Like Tataraus said, trebuchets/catapults can do that too, with far better accuracy. This would be a great way to use a massive area effect version of a technique of mine, called "peebagging".

I invented this just recently. In the campaign, I was dropped down to 5 INT the day before and was trying to act accordingly, like I still trusted my intelligence but it just wasn't there. The players were all fighting each other in the middle of a war. My brilliant strategy was to go straight for the wizards (and the wizard player) while on horseback, but the smarts stopped there. Besides having no real plan for defense (I figure I survived merely because I wasn't considered a serious threat by anyone but the player wizard, who kept botching his save or lose spells against me), my whole attack consisted of peeing in a bag of rations and throwing it at him by horseback. Hence, peebagging.

This actually nearly had a two-fold devastating effect. One, he had to make a fortitude save to avoid being sickened. Two, he had to make a reflex save to block the stuff from getting in his spell component pouch or spellbook and ruining everything. He might have made the saves, but his honor will never, ever be restored.

Now- what if you filled a bag of holding with rations and pee, then exploded it with the contraption you've created? It would be a terrific way to break morale or contribute to a spreading disease, making it perfect for sieging somewhere. As a way to enrage an intelligent but vain enemy/monster, I'd say it's a sure-fire win. Also, you get to use the term "peebagging", and that alone is a pretty good reason.

[earlblue]

Hmm... check this out:

http://www.madehow.com/Volume-6/Springs.html

Unless your technology level is sufficient... you might not even have springs.

Not metal ones anyway.

OBeQuiet UWannaBe.

[Arang]

... contribute to a spreading disease ...

Urine is actually sterile, so unless the rations are rotten you wouldn't accomplish much.

[/nitpick]

'Course, there's other stuff that's, shall we say, readily available, that will get the job done, especially if it gets in wounds.

[mostlyharmful]

Combine bags of holding with a flight capable player (magic item, spell, half-celestial, whatever) and a cohort with alchemy.... then start calling down naplam runs on the oncoming orc horde. The Pc simply flys over the biggest concerntration of gribbllies with all dozen bags pointing downwards with their openings tied with slipknots, pull tag and release the firey doom of two months worth of alchemists fire, along with nails and caltrops and Oil flasks to make uo the weight.... BOOOOOOM, flamey death rains from above.

[Viscount Einstrauss]

My god. Crapbagging. A new and exciting way of dishonoring my foes.

[Zim]

I've always wanted to use shrink object combined with stick and a bunch of big ol' rocks. Stick the shrunken rocks to a ceiling or an enemy's helmet and then dispel the shrink effect. Smoosh.

[kjones]

I recall a spell combo (that was written for 3.0 but probably still works) that involved shrink item, levitate, and wall of iron. Stick would probably work just as well.

Hm... off to the trap-maker's!

[Truwar]

Why? You want to fling rocks? Dude, its called catapult or trebuchet, and the actually work as well as being less expensive. They might not throw as much but it will be loads more accurate and effective. This thing will just scatter 1500lbs of rocks if it even does that.

Actually, they are not all that much less expensive than a bag of holding. They also take days to set up (at least in the case of the trebuchet) and the last time I checked, you could not fit either a catapult OR a trebuchet in your backpack.

As far as accuracy, you could probably improve upon that with a light pole framework. Although several hundred fist sized stones might be even more effective.

It pretty much all comes down to physics and DM rulings however. The momentum of four ropes and a leather bag are not going to be enough to launch a 1500lb boulder anywhere. So unless the DM rules that objects leaving the bag travel at the same speed as the bag is (which is an arguable position) then it would not really work.

[Lapak]

Urine is actually sterile, so unless the rations are rotten you wouldn't accomplish much.

[/nitpick]

'Course, there's other stuff that's, shall we say, readily available, that will get the job done, especially if it gets in wounds.

I can't believe I'm contributing to this discussion, but this comes up way too often to go unrefuted.

Urine is only sterile when it exits the body; it very rapidly becomes a fertile base for all kinds of unpleasant bacteria when exposed to the outside environment.

[....]

Otiluke's Resilient Sphere + As many shrunken vials of water you can get + summoned rat= tie the vials of water onto the rat and cast Sphere on it. Dismiss the rat. Dismiss the shrink effect. You've now got compressed water in the unbreakable sphere. Assuming reality dosn't collapse, roll said sphere into whatever mass of foes you're fighting and then dismiss the sphere. Boom.

Works even better with alchemist fire.

[Solo]

You can't move a Resilient Sphere.

[Grug]

That would be a fun spell. Giant spheres of force with people inside. Imagine a giant pinball table as a means of torture or recreation.

[Mad Wizard]

If there's a way to make an item immune to being smashed into tiny bits, put a decanter of endless water in on "Geyser" and made invulnerable in a resilient sphere. When the sphere is dismissed, boom.

[RAGE KING!]

You can't move a Resilient Sphere.

you can hide it and wait for them to walk by.

[Bauglir]

Just as a minor question, doesn't turning a Bag of Holding inside out render it useless, thus making this a very, very expensive tactic?

[Green Bean]

Just as a minor question, doesn't turning a Bag of Holding inside out render it useless, thus making this a very, very expensive tactic?

Nope. It just empties it out, and you have to turn it right side out to use it again.

[Kel_Arath]

To the people bashing with catapult/tebuchet idea, as Truwar kindly pointed out they are hard to move and cost alot (maybe not as much as type IV bag of holding but still) also they cant fling 1500lb rocks, only a few hundered pounds. As for them being acurate... ya, against giant walls, and require several test shots usually. But imagine an army getting hit with a spray of 1500lbs worth of rocks.. ya...

[AtomicKitKat]

Otiluke's Telekinetic Sphere is a couple levels up, and can be moved.

Corpsebagging. Pick up the dead from the previous assault, stuff them into the bag, then repeat.

[Jack_Simth]

Otiluke's Resilient Sphere + As many shrunken vials of water you can get + summoned rat= tie the vials of water onto the rat and cast Sphere on it. Dismiss the rat. Dismiss the shrink effect. You've now got compressed water in the unbreakable sphere. Assuming reality dosn't collapse, roll said sphere into whatever mass of foes you're fighting and then dismiss the sphere. Boom.

Works even better with alchemist fire.

1) Resilient Sphere doesn't work; it can't move - you need Telekinetic Sphere.
2) You need Line of Effect to Dismiss a spell, which a solid, unbreakable, sphere of force should block. You'll need to be inside.
3) It's a standard action to Dismiss a spell. You'll need to do this individually for each shrunken vial.

Now, if you have the rat working with a Decanter of Endless Water in “Geyser” mode, you can get a similar effect.... assuming, of course, that the back pressure doesn't simply stop the water flow.

[Chronos]

Otiluke's Telekinetic Sphere is a couple levels up, and can be moved.

It can, but it's an 8th-level spell. By the time you have 8th-level spells, you should have plenty of opportunity to wreak havok by other means.