Explosions

[Pnick]

Just double-checking — grenades, explosives and artillery cause impaling damage, right?

Edited May 13, 2021 by MOB

[klecser]

Page 405 Keeper rulebook: "(i) - Indicates a weapon category or specific weapon which can impale."

The entire category is marked!

[Pnick]

Thanks.

Is there a universal rule for decreasing levels of damage the further out of the direct blast radius?

The only rule I can find is for the hand grenade and dynamite sticks —  'Each delivers 4D10 damage to those within 3 yards, 2D10 to those within 6 yards and 1D10 to those within 9 yards' —   but surely there must be similar rules for C-4, mines, mortars, grenade launchers, field guns et al?

[Lloyd Dupont]

I think... (at least it is the rule in BRP IIRC) that they lose 1 dice per meter beyond blast radius.

[SDLeary]

5 hours ago, Lloyd Dupont said:

I think... (at least it is the rule in BRP IIRC) that they lose 1 dice per meter beyond blast radius.

Thats what I remember. I would amend further depending on environment. If your playing Cthulhu Rising for example... thin atmosphere I would reduce by half each step, heavy atmosphere by one for every two bands.

SDLeary

[Ema Nymton]

In addition to the grenade/dynamite example, Keeper Rulebook p406 has guidance for damage based on radius of effect:

2 yards, 3 yards, etc.: Damage radius of explosion in yards; at up to double the range, the damage is halved. At up to triple the range, the damage is quartered. Beyond that damage is ignored.

p.405 lists the most common explosive devices and relevent dam/radius

[Pnick]

A question and some house rules that I found on Reddit relating to explosives.

The question: why, when all other explosives aside from those that are thrown are covered by Demolitions, is a blasting cap the purview of Electrical Engineering?

Actually, looking again, the rules seem to be inconsistent: in the explosives stats chart on page 254 of the Investigator Handbook the blasting cap is the only explosive governed by Electrical Engineering. However, on page 105: 'Electrical Repair may also be used in conjunction with modern explosives, such as blasting caps, C-4 plastic explosives, and mines.' So how does it work, can Electrical Engineering be swapped with Demolitions, like for like? In that case, Demolitions becomes a redundant skill.

Here's the house rules regarding handling explosives copied from elsewhere; comments welcome:

Using the Demolition skill:

Failed - the investigator can't set it up right.

Pushed failed - it goes off instantly in their face.

Pushed success - as a regular success.

Success normal and hard - goes off at the set time.

Success extreme - goes off at the set time and does max damage.

Success critical - goes off at the set time and something else that is wanted also happens.

Damage wise - Dynamite/hand grenades are 4d10 damage at 3 yds/2d10 at 6 yds/1d10 at 9yds.

Range is using the Throw skill with a max range of STR score in feet.

 

[Atgxtg]

1 hour ago, Pnick said:

A question and some house rules that I found on Reddit relating to explosives.

The question: why, when all other explosives aside from those that are thrown are covered by Demolitions, is a blasting cap the purview of Electrical Engineering?

I think it's because most blasting caps are electrically detonated. However, most vehicles have an electronics ignition and yet don't fall under electrical engineering.

 

1 hour ago, Pnick said:

Actually, looking again, the rules seem to be inconsistent: in the explosives stats chart on page 254 of the Investigator Handbook the blasting cap is the only explosive governed by Electrical Engineering. However, on page 105: 'Electrical Repair may also be used in conjunction with modern explosives, such as blasting caps, C-4 plastic explosives, and mines.' So how does it work, can Electrical Engineering be swapped with Demolitions, like for like? In that case, Demolitions becomes a redundant skill.

I would say that Electrical Engineering could be used to make explosives detonate, but wouldn't help with estimating how much explosives you you need, or how to place them correctly for best effect. That would seem to make the most sense to me, and I do have a degree in electronics. Yeah, I could probably wire up a change and make it go boom- that's easy, but nothing about blowing things up was ever covered in my Electronics classes, other than how to avoid it my circuits from doing so. 

In game terms I see this as you need the guy with Demolitions skill to plan out and set the whole thing up properly, but once that is done, anyone with Electrical Engineering can do the wiring and set off the charges. 

But that's all just my thought, nothing official. 

[EricW]

Explosives are really complicated, I think you could drive yourself nuts trying to make the rules realistic.

I made a lot of explosives as a kid, its what you did back in my day if you were smart, in the days before internet.

Fuses are unreliable - sometimes they burn much quicker than they should. Sometimes they pause, then suddenly finish burning and detonate after you conclude the explosive is a dud and have picked it up in your hand.

Electronic fuses - there is a reason people are rigorously careful with twisting wires on their detonator supply, making sure the electricity is physically disconnected before wiring up the detonator, then being really careful after the detonator is connected. Electric circuits can leak enough current to prematurely set off the detonator. Even static electricity has been known to set off detonators. 

Explosives and damage depend on a lot of factors, whether the explosion is contained, what the container is made of, whether the container fragments or comes apart in 2-3 big pieces. If you blow up a firecracker on your hand your hand will sting. If you close your fingers on the firecracker you could lose a few fingers. I don't recommend anyone test this - we were crazy lucky. None of us tried closing our fingers.

An underwater explosion is far more dangerous if you are underwater, than an equivalent explosion in the air - water conducts the shockwave much better than air.

But if you want to contain the collateral damage when say blowing a bank vault, you cover the explosive with big bags of water, to absorb the blast.

Gelignite and dynamite, at least old formulations, can sweat nitroglycerine. This makes out of date or poorly stored explosives extremely dangerous, the drops of nitroglycerine could set off the explosive if dropped or heated.

It is entirely possible to make extremely powerful explosives out of a few readily available household items - but I hope you understand if I don't explain how to do this.

[Atgxtg]

5 hours ago, EricW said:

Explosives are really complicated, I think you could drive yourself nuts trying to make the rules realistic.

LOL! That's probably true about just about everything. We end up making decision about what to simply all the time in gaming. In the end we just sort of pick a compromise between easy of play and enough detail to "sell it" to the players.

 

5 hours ago, EricW said:

It is entirely possible to make extremely powerful explosives out of a few readily available household items - but I hope you understand if I don't explain how to do this.

ROTFL. I saw a friend almost get decapitated by a little storage tin playing around like that. The blast unrolled the tin, which flew right by his neck like a square metal Frisbee. Of course this was on the same day that I made powerful poisonous gases out of a few readily made household chemicals. I cleared out a hornets nest in a garage that way partly to prove that it was indeed true. How we survived our teens is the real question. 

[EricW]

10 hours ago, Atgxtg said:

ROTFL. I saw a friend almost get decapitated by a little storage tin playing around like that. The blast unrolled the tin, which flew right by his neck like a square metal Frisbee. Of course this was on the same day that I made powerful poisonous gases out of a few readily made household chemicals. I cleared out a hornets nest in a garage that way partly to prove that it was indeed true. How we survived our teens is the real question. 

I had the best Grandpa, WW2 artillery machinist. When I was 7 he said “I know you kids are going to mess with explosives, so I’ll show you how to do it right”. Probably the only kid in the neighbourhood who knew how to blow a bank vault, or bring down a bridge or building.

Edited May 14, 2021 by EricW

[Pnick]

Well this thread has taken a turn. Relative parental laxity nostalgia.

[Atgxtg]

13 hours ago, EricW said:

I had the best Grandpa, WW2 artillery machinist. When I was 7 he said “I know you kids are going to mess with explosives, so I’ll show you how to do it right”. Probably the only kid in the neighbourhood who knew how to blow a bank vault, or bring down a bridge or building.

That's the way to do it!

 

2 hours ago, Pnick said:

Well this thread has taken a turn. Relative parental laxity nostalgia.

I suppose when you get into something destructive, it brings back memories of childhood.

[Pnick]

Another issue — that maybe is resolved in the rules somewhere — what happens with a thrown explosive if it misses? It still explodes, and where it lands will determine who is caught in the radius of the blast.

A lot of these issues have reared their head now that VTTs are a lot more the de facto mode of play. When you are using a map, with clear yard measurements between all the actors involved, you look for more specific answers to issues that would have previously been 'theatre of the mind-ed' away.

Also, the tactical element is fun.