D&D 5E Never Give Them Unlimited Black Powder

[Ovinomancer]

Saruman's bomb wasn't black powder or gunpowder, it was whatever magics Saruman cooked up, and called the Fire of Orthanc. As Saruman was the most powerful of wizards prior to Gandalf taking the white, and who created an entire new race of half-orc, saying that the Fire was just gunpowder is really selling Saruman short. Luckily, he's fictional, so no worries.

 

[Aelryinth]

Saruman's bomb wasn't black powder or gunpowder, it was whatever magics Saruman cooked up, and called the Fire of Orthanc. As Saruman was the most powerful of wizards prior to Gandalf taking the white, and who created an entire new race of half-orc, saying that the Fire was just gunpowder is really selling Saruman short. Luckily, he's fictional, so no worries.

See? Alchemical Gunpowder ftw!

 

[Don Durito]

It doesn't have to be unlimited, you know. It has to be enough to destroy their enemies. There is a HUGE difference there, especially with storage/shrinking magic.

Where are they getting it from? Who's making it for them? Or who are they stealing it from?

It's a resource. If PCs control the supply then someone else wants it. Probably someone with the resources to be a challenge even if the PCs have the gunpowder.

Not really seeing this as a unique kind of problem. If you give the players a bag of holding they may do clever things with it. Isn't that the point of things?

If the PCs are really clever that may trivialise some encounters until the GM catches up. In my experience that's usually a lot of fun.

 

[Aelryinth]

Where are they getting it from? Who's making it for them? Or who are they stealing it from?

It's a resource. If PCs control the supply then someone else wants it. Probably someone with the resources to be a challenge even if the PCs have the gunpowder.

Not really seeing this as a unique kind of problem. If you give the players a bag of holding they may do clever things with it. Isn't that the point of things?

If the PCs are really clever that may trivialise some encounters until the GM catches up. In my experience that's usually a lot of fun.

It's an alchemical item. They can make it for themselves. That's one of the problems with this.
Clever things are nice. Breaking a campaign is not. The whole thing is that this has to be carefully managed, or it DOES break a campaign. In most cases, it is much easier simply not to allow black powder.

 

[Bacon Bits]

But all of those barrels and kegs would have been stored inside a relatively small stone-walled chamber, and that would then have become the pressure vessel for the explosion. The entire chamber would have fragmented and showered the area with masonry shrapnel, and if any part of it was a supporting wall for the rest of the fortification, the secondary structural damage could have been extreme.

The same number of kegs and barrels out in an open field wouldn't cause nearly as great an explosion - but would also be much easier to be hit by a stray shot.

No, the point is that they do. The same amount of gas is released whether the barrel is indoors or outdoors. The only difference is how that energy is directed.

The point is that you can't on the one hand say that "oh, it's just destroying the barrel and that's not that strong" and then show that the same same event in a structure can completely level that structure. Yes, containing an explosive in a room causes the energy to be directed against the walls of the structure, but that's still the same energy being released inside the room to the occupants. That pressure doesn't just blow past them. And much of that gas had to have been once contained in large part by the barrel itself.

But let's back up and look at the "barrels aren't that strong so they wouldn't explode with that much force" argument.

Every year people routinely severely injure or maim themselves with firecrackers and salutes. Loss of digits or whole hands is common. Those are a very small amount of powder. M-80s are typically said to hold about 3-5 grams of powder -- flash powder, yes, but still a low explosive powder -- wrapped up in cardboard and sealed with wax or glue. You can't tell me that an iron-bound wooden barrel or keg is less capable of containing pressure than a cardboard tube. Bear in mind, too, that barrels are often designed to contain wine, beer, and similar fermenting liquids. Barrels are capable of holding significant pressure just by being barrels. Powder kegs would likely be constructed to be as water tight as feasible, since wet powder doesn't burn at all.

Similarly, cardboard isn't particularly known for it's ability to be deadly shrapnel, while a wooden barrel would shiver itself. Further, if you're going to make a keg bomb you can do something as simple as pack it with stones, line the outside with nails, or mix in metal scraps.

 

[Ovinomancer]

See? Alchemical Gunpowder ftw!

Right -- if you're invoking magic, then you aren't talking about black powder (or gunpowder, which is a different thing altogether). Magic bombs are magic bombs -- they're whatever you want them to be and any issues you have with them are your issues. This is a case of being lifted on your own (magical) petard.

If you don't know the reference, the saying comes from siege warfare, where sappers would dig trenches or tunnels up to fortification walls and plant crude bombs, call petards, at their base. The setting and lighting of these was tricky even when not being shot at and having things thrown down at you, so accidents happen. At which point the sapper would be lifted (blown upwards) on his own petard.

 

[Aelryinth]

Right -- if you're invoking magic, then you aren't talking about black powder (or gunpowder, which is a different thing altogether). Magic bombs are magic bombs -- they're whatever you want them to be and any issues you have with them are your issues. This is a case of being lifted on your own (magical) petard.

If you don't know the reference, the saying comes from siege warfare, where sappers would dig trenches or tunnels up to fortification walls and plant crude bombs, call petards, at their base. The setting and lighting of these was tricky even when not being shot at and having things thrown down at you, so accidents happen. At which point the sapper would be lifted (blown upwards) on his own petard.

You know, it is an alchemy check to make the stuff, NOT a chemistry check, right?

 

[Don Durito]

It's an alchemical item. They can make it for themselves. That's one of the problems with this.
Clever things are nice. Breaking a campaign is not. The whole thing is that this has to be carefully managed, or it DOES break a campaign. In most cases, it is much easier simply not to allow black powder.

OP just said Black Powder, not alchemical black powder. Not that that makes any real difference - it still needs to be made from something and requires time and money to make. If they're building some kind of massive alchemical factory that attracts attention.

I really don't get it. What is supposed to happen here? The PCs are going to take out there enemies by cleverly smuggling barrels of black powder into their headquarters and lighting a fuse, while making sure they are out of range when they explode?

This is a ... bad thing?

It's a tool. It's not an "I win" button. It requires some degree of logistics and planning to make use of, and the world around them will quickly adjust if they keep pulling the same trick (the effects are not exactly all that subtle).

 

[Ovinomancer]

No, the point is that they do. The same amount of gas is released whether the barrel is indoors or outdoors. The only difference is how that energy is directed.

The point is that you can't on the one hand say that "oh, it's just destroying the barrel and that's not that strong" and then show that the same same event in a structure can completely level that structure. Yes, containing an explosive in a room causes the energy to be directed against the walls of the structure, but that's still the same energy being released inside the room to the occupants. That pressure doesn't just blow past them. And much of that gas had to have been once contained in large part by the barrel itself.

But let's back up and look at the "barrels aren't that strong so they wouldn't explode with that much force" argument.

Every year people routinely severely injure or maim themselves with firecrackers and salutes. Loss of digits or whole hands is common. Those are a very small amount of powder. M-80s are typically said to hold about 3-5 grams of powder -- flash powder, yes, but still a low explosive powder -- wrapped up in cardboard and sealed with wax or glue. You can't tell me that an iron-bound wooden barrel or keg is less capable of containing pressure than a cardboard tube. Bear in mind, too, that barrels are often designed to contain wine, beer, and similar fermenting liquids. Barrels are capable of holding significant pressure just by being barrels. Powder kegs would likely be constructed to be as water tight as feasible, since wet powder doesn't burn at all.

Similarly, cardboard isn't particularly known for it's ability to be deadly shrapnel, while a wooden barrel would shiver itself. Further, if you're going to make a keg bomb you can do something as simple as pack it with stones, line the outside with nails, or mix in metal scraps.

Honestly, as far as the barrel being shrapnel goes, the radius at which the overpressure wave will kill/maim you is about the same as the lethal wooden splinter range. Turns out that wood makes pretty poor shrapnel, and the many stories of wood exploding from cannon shot in ship combats was very unlikely to actually happen. Now, if you do the metal bits, yeah, you're in business.

But, the Gunpowder plot was bad because the perps actually knew their stuff, had good gunpowder, well packed barrels, and planned to place them in a stone walled undercroft where the main hall had a wood floor and wood roof. The blast, had it been well timed, would have been channeled by the undercroft, magnifying the upwards blast as the entire explosion could only vent upwards. This would have definitely killed everyone in the building as the floor violently disintegrated upwards, and taken the roof off and, most likely severely damaged the walls as the overpressure wave cleared the undercroft and found purchase in pushing the walls outward. It was an extremely effective plan -- overkill even, if you'll pardon the bad pun. Still, the amount of gunpoweder was very large and cumbersome and the effect was really created by a clever method of fusing and using the undercroft to created a rudimentary shaped charge. They got caught because of the level of effort to do this -- it would have been a hard plot to actually pull off, and they failed at it.

 

[Ovinomancer]

You know, it is an alchemy check to make the stuff, NOT a chemistry check, right?

To make magic boom-powder? Sure. Why do you keep talking about black powder and gunpowder, then?