D&D Engineering Problem

For producing power, I would think you’d be much better off lifting this Decanter up in the air and taking advantage of the free potential energy. This could be as easy as building an overshot waterwheel.

Or, for maximum advantage, build a water tower with a big tank on stilts and a pipe with valve dropping from underneath and leading to your turbine. The limitation on power out is then the height of your water tower and the strength of your materials. A back-of-the envelope calculation is HP = Flow (gall/min)*Pressure(psi)/2000 You’ve got a max of 300gall/min flow, and a 120-ft-high tower will give you 60psi or so. That’s 9HP, minus the (reasonably significant) losses in any turbine. Still, not too shabby.

Actually, in 2nd edition, a round was one minute, there were 60 seconds in a minute, and one round lasted six seconds. Yes, this is inconsistent, hence why they changed it in 3rd.

The item in question still produces 30 gallons per round, with rounds now unambiguously lasting 6 seconds. Another creative use I’ve seen is to put one in a sealed, permanent Forcecube (indestructible except by certain very specific means), and since the flow rate is constant regardless of backpressure, you eventually compress the water in the cube enough to form a black hole. No, I wouldn’t actually allow this, were I DMing.

Finally, my personal favorite D&D perpetual magic motion device is a permant Reverse Gravity spell. Then, just mount a flywheel at the edge of the antigravity field. Or build a sturdy enclosure around the field, with a “ramp” at the top to redirect “falling” items, and roll boulders into the bottom, for a rapid-fire heavy artillery piece. Or put it in a lake, for a permanent fountain. Or put it in the bottom of a boulder-filled valley, for a permanent rock fountain.

My solution is that once you started harnessing the flow for force, the greater elemental spirit on the water plane would start noticing the back pressure on its end. Naturally, it would sluice through a few dozen Water Weirds to investigate, and maybe have a Kraken stick a tentacle in and thrash it about, sort of an interdimensional Roto-rooter.

That is how adventures are born and silly inventive PCs kept humble :slight_smile:

Hmm…might you put something into orbit with a scheme like this? Could you put up some kind of satellite—like a palantir with a lens system to act as a spy sat, or some kind of reflector to aid in communications (maybe you could bound telepathic signals off it, or flashes from a Gummi Scope, or something?)?

Well, if you want to estimate the amount of energy represented by hit points, try here under “Epic Obstacles.” It gives hp ratings to various materials.

Pikers. What you want to do is cast Polymorph Any Object to transmute a sphere of lead into a sphere of plutonium. Any survival problems for the wizard doing this are left as an exercise for the student. :smiley:

In the old GURPS Supers game you could buy a power to create “any liquid” for something like 1 point a gallon. Presumably this meant anything in its liquid state. So, you could drop molten plutonium on an enemy’s head.

Probably not… The spell has a limited volume of effect, such that at max level, you could only make a column 10 feet by 10 feet by 100 high. You might be able to get something into orbit using an Otiluke’s Telekinetic Sphere, though, or an Overland Flight.

We always assumed it meant any liquid that would be liquid at whatever conditions were present when the spell was cast. It still leaves the door open for all kinds of abuses, but not for some terribly hot or cold liquid.

Well, personally, I wouldn’t want to get hit on the head by a gallon of mercury (approximate weight 113 pounds). That’d have to do some kind of damage. Or how about a gallon of a 20% phosgene in toluene solution? That’d probably kill the target once they managed to inhale. Man, I can think of a lot of things that would be unpleasant (any lachrymator, for instance.) Drop a gallon of an isocyanate on your enemy’s head and he’ll be crying so hard he’ll be an easy kill.

A gallon of really strong acid, like concentrated sulfuric acid or fluorosulfuric acid might work too.

Or a concentrated solution of HF. It might take a while, so dump it and run away, secure in the knowledge that your enemy will eventually die a painful death from hypocalcaemia.

Actually, why dick around with plutonium when you could just go straight to antimatter? :smiley:

Best if the caster have a Contingency Teleport or something of the sort, though.

Could you arrange a series of them, in a tunnel or ramp—so that as soon as the payload leaves the area of effect of one spell, it falls straight into the next (kind of a magical version of the V-3 gun’s propellant scheme)?

Of course, some means of evacuating the air from the “barrel” would help, too. Is there a “Vacuum Elemental” you could enslave?

Oh yes, abuse is always a possibility. I would have allowed the mercury, not the phosgene, unless your character had good knowledge of it. You can’t wish for what you don’t know. Just like you couldn’t polymorph yourself into a creature you had never seen.

Sure, but it’d take a lot of castings at 100 feet each to reach orbit. If you’re making them permanent, that’s a big chunk of xp for each, and if you’re not, they only last one round per level. Plus, the spell also has a limited range, so you’ll have to get yourself up near the top of the stack to cast the higher ones. And that’s a pillar with only a 10-foot-square cross section, so unless you build some sort of structure around it to guide your payloads, they’ll probably drift out of the field before they reach the top.

Okay, for the sake of argument, say I actually figure out how to get this to work—I’m kind of guessing it still wouldn’t be the craziest thing ever done in a D&D campaign—are there any other techno-magical (ab)uses for putting something into orbit, besides just long range (or even fractional orbital) bombartment? Could you have a useful analog for a spy, weather, or communication satellite? Could “Brilliant Pebbles” take on a whole new meaning?

You could just enchant an ioun stone for the planet…

Reverse Gravity lasts 1 round per caster level. If you can Extend Spell it, that’s at least 32 rounds (~3 minutes) per casting. It’ll probably require successive castings (and a ~16th level spellcaster), but it’s at least a good start.

Alas, can’t make reverse gravity permanent nowadays, but you could always just enchant a custom magic item with a similar effect.

I don’t know about putting something into orbit, but there’s this epic spell called Nailed To The Sky which puts the victim into low orbit…