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This came up in game tonight. Thunderwave is a spell with Range: Self (15-foot cube). The description reads:

A wave of thunderous force sweeps out from you. Each creature in a 15-foot cube originating from you...

Players Handbook, 282-283

Does the area of effect center on the caster (extending 7.5 feet in each direction), or does it begin from the caster, and extend in the direction desired (for a full 15 feet)?

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No. It is not necessarily centered on the caster (though it can be).

A cube is not a burst power (to borrow a 4e term). The origination point of the cube is anywhere on a face, not necessarily the center. The term face when referring to a cube means the entire square comprising a side.

So you could feasibly center it on yourself, or place yourself in any other point of the cube's effect (and no, you don't have to attack yourself unless you want to).

I wanted to map this out real quick, just so we're all clear. Let's assume we have a 15' cube spell, and let's also use a grid just so we have a bit of clarity, and a limited set of points to operate from. There are 18 possible origin points for a 15' cube, representing two different 3x3 areas (the top and bottom face of a cube). For both of these the graph is the same, but the results are different. If you select the top face, the spell targets the 8 squares in your plane, and the 18 immediately below you. If you choose the origin as the bottom of the cube, then it targets the 8 in your plane and the 18 above you. Now which square is the origin:

 XXX
 XXX
 XXX

Basically, you can be standing in any of the squares that are X and have the burst be those 9 squares. Let's look at a few more examples (Caster is C):

 XCX
 XXX
 XXX

Here you step to a side and have it radiate to your left, right and two rows forward of you.

 XXX
 XCX
 XXX

Here you center it on yourself.

CXX
XXX
XXX

Here you take a corner of the spell and cast it to your left and forward, and radiates out. It seems you should be able to be outside teh area too:

 CXXX
  XXX
  XXX

Since you're adjacent (and heck that could be the middle of a face or the bottom or the top of it. (See the caveat below, this particular form falls much more into the "point" point of origin argument and may or may not be valid in all games.

CAVEAT: There are at least two camps developing around the term "point of origin" used in the text, and depending on which system you came from you may immediately interpret that differently. I have used in this response the version of the term influenced by my 4e experience, which infers that the point of origin is an entire square (this makes a ton of sense when you play with gridded combat as the default, which I do in my 5e games). However, there is a camp that comes from a different point of view that interprets "point of origin" as a singlular point (with an undefined diameter, likely just the part of the cast casting the spell...not sure, I'll let them speak for themselves). This POV would have the caster included in the spell if you cast in the ways that I describe above where the caster is fully within the Xs.

It's important to note that right now both of these interpretations are equally valid and subject to DM interpretation. I'll be using the "point is a whole space unless you don't want it to be" version, feel free to use whichever is most useful in your game (just be consistent about it).

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    \$\begingroup\$ I think you should clarify how one would create a cubic effect centered on the caster. It is not immediately obvious that this is kosher from the rules, but I think would involve setting the origin at the center of either the top or the bottom face of the cube. \$\endgroup\$ – Grubermensch Oct 6 '14 at 3:50
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    \$\begingroup\$ But how does a caster end up in the middle of the effect? You have one illustration (3rd one down), where the caster is not touching the face of that cube? Maybe I'm not visualizing your drawing correctly. \$\endgroup\$ – Besty Oct 19 '14 at 23:26
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    \$\begingroup\$ @Besty You cannot be in the middle of the 3-d effect. You can be in the center of the 2-d plane of the effect (Which tends to be the one that matters). Self is rather a loose interpretation. I'd probably rule that final form invalid in my games, but I feel like with certain versions of "point" it would be a valid form. \$\endgroup\$ – wax eagle Oct 20 '14 at 0:12
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    \$\begingroup\$ In case you want to add the sage advice link: sageadvice.eu/2015/04/29/thunderwave \$\endgroup\$ – Khashir Dec 19 '15 at 5:33
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    \$\begingroup\$ 5 years later, is there clarification regarding this? \$\endgroup\$ – BlueMoon93 Apr 1 at 12:29
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No, Thunderwave is not centered on the caster. And it cannot be. (But it can affect you.)

Jeremy Crawford says so. But he only had 140 characters, so let's explain a bit.


Thunderwave has a range of "Self (15-foot cube)"

So we look at "Range":

Spells that create [areas of effect] that originate from you also have a range of self, indicating that the origin point of the spell's effect must be you. (PHB p.202, emphasis mine.)

And then look at "Areas of Effect":

Cube You select a cube's point of origin, which lies anywhere on a face of the cubic effect.... A cube's point of origin is not included in the cube's area of effect, unless you decide otherwise. (PHB p.204, emphasis mine.)

So the origin's on the caster. If you live in the world of squares, let's say the origin's either in the caster's square or on the edge of it. And the origin is on a face of the cube, so the caster is on a face of the cube. You can get arrangements like:

CXXX    CXX    XXX    XXX
 XXX    XXX   CXXX    CXX
 XXX    XXX    XXX    XXX    (and all the rotational variants)

but not

XXX
XCX
XXX

Unless you're Large or larger.

Then one part of your anatomy can be on the face while another part is at the center of the cube.

               CC
CCX    CCXX    CCXX
CCX    CCXX     XXX
XXX     XXX     XXX
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    \$\begingroup\$ I'm not sure Jeremy is thinking far enough outside the box here. If the point of origin is a face of the cube, why not the bottom one? Cubes are 3-d, that means that you have 6 faces to choose from. Unless he's saying that you can't use the bottom face as a point of origin? \$\endgroup\$ – wax eagle Jan 25 '16 at 14:13
  • \$\begingroup\$ @waxeagle you certainly can. But that still doesn't get you at the center, right? (Unless you're >=7.5' tall and want to use the same anatomy argument as I made for >=Large creatures.) That's a little what I was thinking when I mentioned "rotational variants," but could probably make a lot clearer =) \$\endgroup\$ – nitsua60 Jan 25 '16 at 15:41
  • \$\begingroup\$ ah, you're talking centered in a 3-d sense, in that case, no. But in a 2-d sense, you an definitely center it on yourself (bottom face of cube is and intersection of squares (or the square depending on how your grid works) below you), spell effect extends 15' above the ground head. \$\endgroup\$ – wax eagle Jan 25 '16 at 15:47
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    \$\begingroup\$ @waxeagle sure, in which case you're only centered w.r.t. an observer directly overhead. But that's no different than a caster choosing point of origin anywhere, and an observer on the line connecting caster and cube-center. \$\endgroup\$ – nitsua60 Jan 25 '16 at 15:55
  • \$\begingroup\$ You cannot use the bottom face, because then the caster is standing inside the cube. There's a reasonable chance Jeremy was fully aware of this. In the tweet cited, Jeremy explicitly states (probably to implicate this very situation) the spellcaster cannot be inside the cube. Using the bottom face would place the spellcaster inside the cube. That is, unless you fire the cube directly above your head and into the air, in which case you are hitting nothing around you that's on the ground and less than or equal to your size. Which makes it interesting if you are a small caster vs medium targets. \$\endgroup\$ – Blaise Jan 15 at 18:23
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I disagree that you can center Thunderwave on yourself. The point of origin is on a face of the cube. You could make that point somewhere on the top or bottom, but then the caster's body is included within the cube (only the point of origin can be included or excluded -- the caster's entire body is not the point of origin unless the caster's entire body is on a face of the cube.)

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  • \$\begingroup\$ It really depends on how you define "point of origin." There is a camp who would define it as the entire square that a caster occupies, and another that argues that the "point of origin" is only a point. I'm in the first camp, you seem to be in the latter. That's Ok, though you may want to answer the whole question so that this doesn't find itself deleted by the moderators or the community. \$\endgroup\$ – wax eagle Oct 19 '14 at 21:03
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    \$\begingroup\$ To update this. the DMG defines a point or origin as an intersection of a grid square or hex. \$\endgroup\$ – wax eagle Dec 9 '14 at 16:07
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Imagine it like this and you can see why being in the center doesn't work: you put out your hand and thunderwave comes into being as a vertical 15x15 square of energy (your hand does not need to be centered on it but must touch it). Then that square moves 15', potentially shoving those in the cube area it has now covered. it's a wave that affects a cube area, not itself a cube.

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  • \$\begingroup\$ You drop to your knees and slap the ground. A fifteen-foot square of energy forms on the ground centered on your hand, and moves straight upward. (Of course, this interpretation leaves you wide open to a similarly rules-lawyering DM ruling that you get caught in the blast...) \$\endgroup\$ – John Evans Aug 13 '18 at 23:35
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Actually, based on the description on page 205 of the PHB you could have it radiate from you, but you would be included in the effect if you are trying to catch those around you. You are the point of origin and the cube must be attached to you from a cube facing position. Imagine, therefore, that you have the spell emanate from the bottom of your feet up. This would mean you made a decision to include yourself in the area of affect. You will note they do not specifically say "direction" therefore the direction for which the spell goes could include yourself, and would indeed include yourself if the desired effect is to catch all those around you in the effect.

From the PHB Page 205:

You select a cube’s point of origin, which lies anywhere on a face of the cubic effect. The cube’s size is expressed as the length of each side. A cube’s point of origin is not included in the cube’s area of effect, unless you decide otherwise.

It is that,"Unless you decide otherwise.", that informs the option of you centered in the effect. Your point of origin could exist either within or outside the cube, but if you chose to be within you will have decided to be within the area of effect.

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    \$\begingroup\$ Hello and welcome! You can take the tour for a quick site intro. I have made a small edit to the answer to format the quote from the PHB. Feel free to edit or revert if you don't like it. Regardless, thank you for the contribution! \$\endgroup\$ – Sdjz Oct 14 '18 at 15:32
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For use on a grid (i.e. ignoring verticality), there are only three possibilities:

 CXXX
  XXX
  XXX

  XXX
 CXXX
  XXX

  XXX
  XXX
 CXXX
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  • \$\begingroup\$ Hi, welcome to the site! When you get a chance, please take the tour . This seems like a fine answer, but perhaps you could have a note explaining what the "c" and the "x" represent just for users of the site that might be unfamiliar with it? \$\endgroup\$ – GreedyRadish Oct 5 '16 at 16:45
  • \$\begingroup\$ It seems to me that you're right about there only being three possibilities, but they're not the three you depict. Your numbers 1 and 3 are functionally identical, but it seems you're missing the case where a "corner space" of the t'wave is diagonally across an intersection from the caster. (Imagine if the 'C' in your third diagram were one line further down the page.) \$\endgroup\$ – nitsua60 Feb 11 '17 at 0:19

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