Area Effect and Wall height

[Prof. Á.]

Hello everyone!

I would like to ask a few question: What is the height of an Area Of Effect attack? Is it semi-circle, with the height in the center equal to the radius, becoming smaller and smaller? Or is it 2 yards everywhere?

Also, how tall is the Wall the wall enhancement gives? And can you put the 3x1 wall block in any shape you want? Also, the wall parts are given per level of AreaOfEffect, or by the Radius it would give?

I have searched everywhere, and couldn't find answers. Thank you in advance. :)

[Bruno]

Originally Posted by Prof. Á.

Hello everyone!

I would like to ask a few question: What is the height of an Area Of Effect attack? Is it semi-circle, with the height in the center equal to the radius, becoming smaller and smaller? Or is it 2 yards everywhere?

As per the basic set page 101 : "12’ high, should volume matter". 12' everywhere (which is 4 yards, not two).

Originally Posted by Prof. Á.

Also, how tall is the Wall the wall enhancement gives? And can you put the 3x1 wall block in any shape you want? Also, the wall parts are given per level of AreaOfEffect, or by the Radius it would give?

Most of these are answered in the description of the Wall Enhancement, page 109. The height is as per page 101 (12' tall). To put it in any shape you want, you need to take the second level of wall, who's ONLY point is to let you put it in any shape you want.

"You get a three-yard-long by one-yard-wide wall per yard of radius in your area." (emphasis mine) - so for an attack that normally doesn't have an Area (all of them, I think), one level of Area of Effect gives you 2 yards of radius, so 6x1 of wall. Two levels of AOE gives you 4yards, so 12x1. Three levels of AOE gives you 8 yards, so 24x1.

Originally Posted by Prof. Á.

I have searched everywhere, and couldn't find answers. Thank you in advance. :)

Search in the Basic Set ;) The PDF version is really handy, and you can get it from e23.

[Prof. Á.]

Thank you :)

It looks like I was looking at the wrong place, I was looking at "Area Of Effect"
description. Strange, I expected it to be there.

And whoops, I should noticed the "/yard of radius" bit. And thanks for clarifying the +60% version. I thought that meant the decorative shape of the wall.

[Bruno]

No problem. I abuse the CTRL-F (find) feature heavily, it really helps find those fiddly little rules.

[Agent]

Originally Posted by Bruno

As per the basic set page 101 : "12’ high, should volume matter". 12' everywhere (which is 4 yards, not two).

So it's 12' high no matter how many levels of Area Effect? Like with hundreds of yards of radius? Seems strange for someone modeling big explosions that the height is purely static. I'm visualizing this going off with its central point high in the air and it seems more like a fire-deep-dish-pizza than a fireball...

[Bruno]

But you don't make explosions with Area Effect, you make them with Explosion (page 104) - so yes, of course AOE is inappropriate.

[Agent]

Unfortunately, the Explosion modifier doesn't seem to indicate a further consideration of height either, nor do the rules on page 414 seem to specifically reference it. It would appear 'explosions' would follow the same default considerations as Area Effect unless I'm missing something therein or in another book.

As to Area Effect being inappropriate for 'explosions' I guess it depends on your definition. I was just using the term generically. As an example, in Powers under Heat/Fire sample abilities (pg 139), you have Fireball that indeed has Explosion, but Inferno several examples later is Area Effect based. And these are designed to be used in multiple levels.

Conceptually, you could say supernatural effects with Area Effect just work that way, but I'm curious if this is intentional and whether larger height is indeed static and might require a further modifier, or is legitimately assumed but not covered specifically.

[Bruno]

Originally Posted by Agent

Unfortunately, the Explosion modifier doesn't seem to indicate a further consideration of height either, nor do the rules on page 414 seem to specifically reference it. It would appear 'explosions' would follow the same default considerations as Area Effect unless I'm missing something therein or in another book.

I think what you're missing is that it's not an area effect. It's a point effect, and everything refers to distance from the origin point. I'm just not sure how the area description can possibly apply to it, because otherwise it's also 2 yards maximum radius as well, as no hard radius is specified.

Originally Posted by Agent

As to Area Effect being inappropriate for 'explosions' I guess it depends on your definition. I was just using the term generically. As an example, in Powers under Heat/Fire sample abilities (pg 139), you have Fireball that indeed has Explosion, but Inferno several examples later is Area Effect based. And these are designed to be used in multiple levels.

Which suggest to me that the Inferno isn't an explosion. There are many things that aren't explosions, and for them using the Explosion modifier isn't appropriate.

I guess what I'm not really following is what the existance of something using Area Effect has to do with the explsions? There's nothing really "generic" about the term, after all. Outside of excitable advertisers scripts[1], we don't refer to things with a volume as being "explosions". Area Effect makes all kinds of things into volume-filling abilities (often in combination with Affects Others). Explosion makes things that go boom, which is why it's restricted to a limited range of base advantages.

[1] I'm sure I've seen "an explosion of flavor" before somewhere.

[Not another shrubbery]

Originally Posted by Bruno

[1] I'm sure I've seen "an explosion of flavor" before somewhere.

Googling the phrase gets several hundred thousands of hits, if that helps :)

I have mentioned before that I usually assume AE creates domes (on a surface) or spheres (in mid-air). That has not been a balance problem thus far.

[jeff_wilson]

Here is reproduced correspondence between myself and Kromm that has not yet appeared in the FAQ:

> What is the canonical way in GURPS to increase the height and volume
> > of areas affected by Control, other abilities with inherent areas,
> > and those enhanced by Area Effect? This is regarding the use of said
> > abilities on sizeable objects like buildings and planets.

There's no canonical means to do that, but you can fudge it with Wall,
Permeable, +60% on any ability that has both Area Attack and Persistent
. . . or one that works as if it did (Control, for instance, affects an
area and persists indefinitely while you concentrate). Then because the
+60% version of Wall allows reshaping, you can stack up your wall into
whatever shape you like; e.g., a two-yard-radius Area Effect gives you
two segments 3 yards long, 1 yard wide, and the customary 4 yards (12')
high (see the box on p. B101 for that last bit). That's 12 cubic yards.
After that, every doubling of radius also doubles this volume. About 67
levels of Area Effect will do the job for Earth.

> Doen't this make a lot of existing builds ludicrously flat

Flat? Yes. Ludicrously? No. It's called "game balance." Allowing a PC
to have a power whose height "just feels right" is asking for trouble.
You get what you pay for, so to speak.

> > How about explosions and cones?

Explosions are spherical to begin with. All that matters there is the
distance from the origin, not the plane. Being 4 yards from a blast
means dividing its effects by 12, 8, or 4, depending on enhancement
level. It doesn't matter whether you're 4 yards away horizontally or
floating 4 yards in the air.

Cones are planar wedges, like Area Effect but triangular instead of
circular.