GURPS 4e Magic Silence vs GURPS Explosions

[Eric Funk]

Greetings Brain Trust!

In GURPS, Black Powder is TL3, and works by causing a pressure wave (HT184), essentially a loud sound.

https://www.ifatactical.com/blog/how-gunpowder-works/

For this purpose let's say a keg of gunpowder is involved, from p. HT184 it is listed at 6d x14 cr ex damage. (Explosions on B414 suggest a cr ex explosion will start secondary fires and such an iron-bound oak keg might add [1d] "incidental fragmentation".)


Now bring in MAGIC 4e, p. 171: Silence (Area)*. "Creates an area of quiet. No one within this area can hear anything, and nothing that happens in this area makes any sound." I would assume this would protect against the Concussion spell (p.M26).

A few related cases can occur as the wizard casts the spell:
A) just over the keg. The wizard is standing next to it when it goes off...
B) just over himself standing next to the keg.
C) Both in the area of effect
D) An area of effect between the two.

If the magic slows down the waves so they are no longer harmful it would not hurt anyone directly with the event horizon of the explosion but could still set fires and propel fragments from the initial blast...

Your thoughts?


Thanks!


* and Wall of Silence M172

[Fred Brackin]

Originally Posted by Eric Funk

Your thoughts?

Sound waves and explosive overpressures are pretty different things and I wouldn't let any Silence-like spells provide protection from overpressures.

You could make the explosion quiet but you wouldn't stop an damage.

[Eric Funk]

Originally Posted by Fred Brackin

Sound waves and explosive overpressures are pretty different things and I wouldn't let any Silence-like spells provide protection from overpressures.

You could make the explosion quiet but you wouldn't stop an damage.

Ah, that makes sense. With the precedent of Darkness spells that would stop what humans see but let, say, radio, etc pass. Similarly a Silence spell would let wind pass through, just no one would hear it.

Whew. That will let "operation hush-a-boom" continue.
Thanks!

[Willy]

I would also say a Silence spell shouldn´t cancel a expolsion.

I always tought of the silence spell, as cerating magically a wave shift exactly the opposite curve of the sound you want to hush. This cancels out the noise for the ear and you hear nothing, but the pressure wave aka damage from explosion would still happening completely unmodified.

[David Johnston2]

Originally Posted by Eric Funk

Now bring in MAGIC 4e, p. 171: Silence (Area)*. "Creates an area of quiet. No one within this area can hear anything, and nothing that happens in this area makes any sound." I would assume this would protect against the Concussion spell (p.M26).

In addition I would like to point out that magic is limited by the visualization ability of the caster. Which is to say that Silence would probably only block the range of sound that the caster can or could once hear and would definitely not block ultrasonic or subsonic sounds when they lack the TL to know of such things.