Forty foot cube or fourty cubic feet big difference.

[Bree_Yark]

Seeking some guidance:

Minor Image:
This spell creates the illusion of an object, creature or force as
visualized by the caster. Its area of effect is a 40 foot cube + 10
cubic feet per level.

MAJOR IMAGE, Level 3 illusionist
The image persists for 3 rounds after the caster ceases
concentrating. The image disappears if an opponent makes the
saving throw. The spell affects a 40 cubic foot area + 10 cubic
feet per level.

A forty foot cube 40x40x40 = 64,000 cubic feet
40 cubic feet is 3.4 x 3.4 x 3.4 the size of a large box or end table.

HUGE difference.

Assuming an illusionist wants to cast an illusion of a solid 1 foot wall using either spell (using the 40 cubic feet rule) they would have to be 6th level. That seems a bit high....

The illusion of a simple pit would be 10 x 10 x 10 impossible to cast until 93rd level.... :O

[Treebore]

In my experience Cubic foot and foot cubed are the same thing.

[Captain_K]

cubic feet or cubic any length measurement is a volume and you would need to take the third root to get the x, y, z dimension of a cube (geometric shape, a square in 3d if you will) to let you visualize how big that volume would be as a cube.

Thus the initial spell is a "40 foot (per side) cube" or 64,000 cubic feet. So it starts out being able to affect an area the size of several shipping containers.. pretty darn big.. but then you add that silly little bit per level. At 10th level you would add 100 cubic feet to 64,000 cubic feet for 64,100 cubic feet increasing your size cube to 40 feet on a side AND 0.073 inches! Thus making the level bump not worth worrying about.

So that is the real math and how the spell IS written... not to be rude, but Tree is likely right, the Trolls might have not gotten the math terms quite right or its a type-o or its "errata" needing fixing. Logically, the wording should be, "a 40 foot cube that increases in size by 10 feet on a side per level". Thus by 5th level its a cube 80 feet on a side.. a HUGE volume. Basically as big as a Titan or smallish dragon. Likely this is what the trolls wanted.

Fix the math as you wish, a static 40 foot cube or as noted above.

Math rules... when you use it right.. it kills when you don't.

[alcyone]

This is useful if you are building swimming pools or working for NASA, you wouldn't want to get this wrong.
But since this is based on d20 where everything is in 5' squares, you can be sure they meant the simpler and larger one.

[Treebore]

Cubic foot. ... It is defined as the volume of a cube with sides of one foot (0.3048 m) in length. Its volume is 28.3168 liters or about 1⁄35 of a cubic meter. At 60 °F, a cubic foot of water weighs 62.36630 pounds (28.28888 kg

The cubic foot is an imperial and US customary (non-metric) unit of volume, used in the United States, and partially in Canada, and the United Kingdom. It is defined as the volume of a cube with sides of one foot (0.3048 m) in length. Its volume is 28.3168 liters or about 1⁄35 of a cubic meter.

I must be missing something, because when I look up cubic foot versus foot cubed, I get the same definition.

[Go0gleplex]

Tree...are you questioning Cap's terms or the OPs? Cubic foot and foot cubed are the same thing. However stating a measurement as a cube of X distance per side defines a geometric area, not a unit of measurement. So 40 foot cube (area) is different than 40 cubic feet (unit of measure).

Bree...no. A 10x10x10 pit can be cast with the spell when initially gained. You are thinking three dimensionally for required area but since it is an illusion, it can be much like a chalk painting. A single plane with the illusion of depth and volume as long as it is presented in a way that is believable by those observing it. all you the spell caster needs is to be able affect 100 square feet or a 10x10 square. Same thing for the wall. As long as the wall is only observable from one plane and not the sides which would then require the illusion to represent a z-dimension, only the area observable needs to be accounted for by the spell.

[Captain_K]

I tried to be very specific and I re-read the spell.. it defines a "cube with each side being 40 foot in length".. then they (stupidly) make the level add on in volume terms which really makes a mess of things. They define the size of a cube NOT its volume for the base of the spell then add level increase in trivial volume adds.. as my example details.

[Go0gleplex]

I tried to be very specific and I re-read the spell.. it defines a "cube with each side being 40 foot in length".. then they (stupidly) make the level add on in volume terms which really makes a mess of things. They define the size of a cube NOT its volume for the base of the spell then add level increase in trivial volume adds.. as my example details.

Out of curiousity's sake, I went back to the 3rd printing to see how it was written and found a little bit of difference in language. In both cases it was presented as a 40' cube area + 10' cube area increase. So basically, you are correct with the 40' cube or 64000 cubic feet, then it extends by 10'/level in one dimension of area, or a 16000 cubic foot increase per level.

[mmbutter]

Cubic foot. ... It is defined as the volume of a cube with sides of one foot (0.3048 m) in length. Its volume is 28.3168 liters or about 1⁄35 of a cubic meter. At 60 °F, a cubic foot of water weighs 62.36630 pounds (28.28888 kg

The cubic foot is an imperial and US customary (non-metric) unit of volume, used in the United States, and partially in Canada, and the United Kingdom. It is defined as the volume of a cube with sides of one foot (0.3048 m) in length. Its volume is 28.3168 liters or about 1⁄35 of a cubic meter.

I must be missing something, because when I look up cubic foot versus foot cubed, I get the same definition.

When using single units, it does become simple. A cubic foot (or foot cubed) is indeed a cube 1 foot in each direction (or that equivalent volume). However, there is a large difference between 2 cubic feet and a cube 2 feet in each direction (the latter is 4 times the volume of the former). And an even larger difference between 3 cubic feet and a cube 3 feet in each direction (the latter in this case is 9 times the volume of the former). And so on...

1 cubic foot -> ~28.32l
2 cubic feet -> ~56.63l
3 cubic feet -> ~84.95l

A cube 1 foot on a side -> 1 cubic foot -> ~28.32l
A cube 2 feet on a side -> 8 cubic feet -> ~226.53l
A cube 3 feet on a side -> 27 cubic feet -> ~764.55l

[Treebore]

Well,
I do not see it referred to as being 40 foot per side in the OP desriptions. So as written in the OP, there is no discrepency.

[Captain_K]

not denying any of that. But the spell is clearly written as a 40 foot per side cube.. I think we can all agree this is errata in need of fixing in the 7th printing.. does Traveller already know about this errata?

[Treebore]

Let me re iterate, Cubic foot and foot cube are the exact same thing, they do not have different meanings. They are both 1 cubic foot of area. So the terms, and how they are used , in the actual spell descritpions are 100% correct. The only possibility is maybe it should read CubeD instead of Cube, but in all the math examples I looked up, they did not say Cubed, they said cube, when that word order was used. IE foot Cube. So saying a 40 foot cube is the exact same things as saying 40 Cubic foot. If it is to be confused with anything, it would be a foot rest called a foot cube.

After all, if you have a cube that is made of 40 cubes, each 1 cubic foot, how are you going to measure it? On 3 axis. Why? Because the word Cube is used. So it is not area in either case, it is volume. No where does it say a single side is 40 foot, they used the word Cube. So it is a 40 foot cube. IE not a liinear measure, but one of volume. So each side would be 13.3, for a 40 foot cube, or 40 cubic foot.

Now if they had used the word feet, a linear measure, in either descritpion, I would agree, but they used foot both times. That is inherently volume, not a linear measure.

[mmbutter]

So each side would be 13.3, for a 40 foot cube, or 40 cubic foot.

If each side is 13.3 feet, the volume would be 2,352.637 cubic feet, not 40.

40 cubic feet has each side of the cube ~3.4 feet.

[Go0gleplex]

So saying a 40 foot cube is the exact same things as saying 40 Cubic foot.

Absolutely NOT! You are getting hung up on the word cube Tree. You go to any engineer or surveyor with the above statement and they will tell you the same thing.

You are right, cubed foot is the same as cubic foot. But that is NOT the context of use in that statement. The 40 foot cube is stating a shape, the cube, with a defined dimension of 40 feet per side. Or simpler terms, you are defining the dimensions of a geometric shape. It is not the wording for usage in defining a unit of measurement which is what cubic or cubed foot is. When you say cubic of cubed foot you are stating a unit that as you know is one foot per side in three dimensions. They may seem similar in appearance but they are as different as apples and bananas in context and measure.

When you say 40 cubic feet, you are defining an area of 40 of these units and only 40 of those units. Which would be an area 4' high, by 1' wide, by 10' long or some variation thereof. When you say 40 foot cube, you are defining an area of 40' high, by 40' wide, by 40' long...which is 64000 units of cubed/cubic feet.

[alcyone]

Anyway, the d20 version (from Silent Image) says:

"Visual figment that cannot extend beyond four 10-ft. cubes + one 10-ft. cube/level"

[Tadhg]

This is useful if you are building swimming pools or working for NASA, you wouldn't want to get this wrong.
But since this is based on d20 where everything is in 5' squares, you can be sure they meant the simpler and larger one.

It's a good thing we don't have an illusionist in our Weds metal dungeon crawl ~ or Penny would have to spend the weekend studying this thread.

I know how she feels about rules lawyers, what about rule engineers?

Just kidding to all the participants of this thread.

I for one, am quite interested in the final determination as to the exact meaning of the descriptions in question - for a spell that I don't allow in my games!!

[alcyone]

Well, we have a Bard/Illusionist in the Xylh game, and I allow all illusions no matter how stupid, because I believe so strongly in the truth of the PHB.

[Tadhg]

Well, we have a Bard/Illusionist in the Xylh game, and I allow all illusions no matter how stupid, because I believe so strongly in the truth of the PHB.

LOL!

Oh, but me too - just not after 3rd print and that's the truth!

[Go0gleplex]

Cap and I aren't rules lawyering though Rhu. We're MATH/GEOMETRY lawyering!

Personally I figure the CK is gonna run it how they run it.

[Tadhg]

Cap and I aren't rules lawyering though Rhu. We're MATH/GEOMETRY lawyering!

Personally I figure the CK is gonna run it how they run it.

Haha. I was terrible at al g bra - but excelled at geometry and so I've been able to follow the discussion somewhat (hmm, was it 47 years ago that I did HS geo and studied equilateral, isosceles and scalene triangles?). Whoa, nevermind.

I think I saw Bree-yark online some moments ago . . wonder what he has to say!!!

[Bree_Yark]

Most illusion at least at lower level are going to be small. I'm 4th level right now so I'm not all that worried about creating large objects but a pit or a wall would be helpful.

If you think about it Most humans are about 12 cubic feet, a bugbear would be about 16 cubic feet. So most humanoids would be easily duplicatable with the spell, but things like a bridge, pit or wall are another story.

[Traveller]

The area of effect is a 40 foot cube, increasing by 10 feet per level.

Sound better?

[Bree_Yark]

The area of effect is a 40 foot cube, increasing by 10 feet per level.

Sound better?

It does, now I just have to convince my CK of that.

[Captain_K]

So saying a 40 foot cube is the exact same things as saying 40 Cubic foot. - not a true statement.

I also want to remind folks, cubes are volumes not AREAS.

I assume this is resolved.

Tree, Sorry, I'm not trying to be a pain here, but Go (10^10^100) and I are correct. I'll throw the full weight of my PhD in Mechanical Engineering behind this, that and 50 cents gets you a free cup of coffee (a full 8 cubic inches of coffee at that).

Best of all, Traveller WILL have it fixed in the latest printing we're all going to get, so it will never be an issue again. Right, you will commit to fixing this one errata?

Bree-Yark, Unless your CK is Trump using alternate facts, you should be fine. If the 40 foot on a side cube is enough volume, you need not worry about the trivial level adds that the current printing states (we assume incorrectly).

I will put a spin on this, since it is a 3D volume, and not a 2D movie screen, and it can move, the amount of "real life" trying to be imitated within that volume and the detail required would cause any illusionist's mind to overload. Every blade of grass, moving creature, changing scene.. no wonder folks get and INT save to "disbelieve" from the likely obvious examples when you look close at details for the "non-real" events happening in a 40'x40'x40' volume of space!

[mmbutter]

The area of effect is a 40 foot cube, increasing by 10 feet per level.

Sound better?

"The area of effect is a cube 40 foot per side, increasing by 10 feet per level."

[Go0gleplex]

The area of effect is a 40 foot cube, increasing by 10 feet per level.

Sound better?

"The area of effect is a cube 40 foot per side, increasing by 10 feet per level."

Not to be throwing gas on things... but does the intent of increase become 10' in one direction or a uniform 10' increase? ie a 40'x40'x40' cube becomes a 50'x40'x40' area with a level increase (as denoted in previous editions) or now increases from a 40' cube to a 50' cube. Thus a difference between 16000 cf increase vs a 64000 cf increase in area affected.

[mmbutter]

Not to be throwing gas on things... but does the intent of increase become 10' in one direction or a uniform 10' increase? ie a 40'x40'x40' cube becomes a 50'x40'x40' area with a level increase (as denoted in previous editions) or now increases from a 40' cube to a 50' cube. Thus a difference between 16000 cf increase vs a 64000 cf increase in area affected.

In one previous edition I looked at, it said "Its area of effect is a 40 foot cube + 10 cubic feet per level."

So, the area of effect would be a cube 40' per side, increasing in size roughly 2' per side for each level. So, at level 5, it would be 50' per side, level 10 would be 60' per side, etc.

[Traveller]

@Captain_K: According to the Trolls themselves, there won't be an extensive errata fix for the 7th Print. Which is why I made a thread for the stuff we find. Reminds me that I have to add a link to this thread to that discussion.

@mmbutter: That does sound better, though perhaps to make it a bit more explicit, try this. "The area of effect is a cube 40 feet per side, increasing by 10 feet per side per level."

[Go0gleplex]

@mmbutter: That does sound better, though perhaps to make it a bit more explicit, try this. "The area of effect is a cube 40 feet per side, increasing by 10 feet per side per level."

That sounds a lot better and clearer Trav. I vote go with that.

[mmbutter]

@mmbutter: That does sound better, though perhaps to make it a bit more explicit, try this. "The area of effect is a cube 40 feet per side, increasing by 10 feet per side per level."

The only problem I have with that wording is that (since the caster starts casting that at 4th level) the *smallest* version is a cube 80ft per side - which seems a bit large for a "minor" image...

Maybe "The area of effect is a cube 10 feet per side for every level of caster." So, 40' at 4th, 50' at 5th, etc.