The rule books quite specifically do not go into exactly how the various spells and other area effects must map onto the squares/hexes of a grid. You are free as a DM or table to choose the method(s) that work best for you. The important thing is that it feel balanced and is applied consistently - so enemy creatures and spells use the same method/template.
The diameter of the base of the cone should be equal to the height of the cone so the circles (from above) should have a diameter equal to the cone length, not a radius of the cone length.
The diameter of the base of the cone should be equal to the height of the cone so the circles (from above) should have a diameter equal to the cone length, not a radius of the cone length.
DMG states:
You select a sphere's point of origin, and the sphere extends outward from that point. The sphere's size is expressed as a radius in feet that extends from the point.
A cone extends in a direction you choose from its point of origin. A cone's width at a given point along its length is equal to that point's distance from the point of origin. A cone's area of effect specifies its maximum length.
As I understand it, a 10ft Sphere has a Radius of 10ft measured from an intersection, thus will cover any square that is at least 50% covered by the effect of the spell. Also a Cone will extend up to the specified range and at any point, it's width matches it's length. Thus 5ft away from the point of origin it is 5ft wide, 10ft away is 10ft wide and so on till you reach the max cone range.
My problem is... Which would be the correct 15ft diagonal cone... The one on the left or the one on the right? On a grid, neither really reaches out 15ft away from the caster, because Pitagoras doesn't apply to fantasy grid worlds apparently.
Left would be more accurate since the width of the cone at the end should be the same as the distance. Right feels more accurate, but is wider than it should be as it's a 90 degree cone instead of roughly 60 degree. Both cover the correct number of squares though so use whichever you like as long as you're consistent.
Playing on Roll20 so not an option for irl effects, sadly.
You can buy a spell templates pack on Roll20 for about $5 which lets you use transparent overlays to just drag and drop onto your map and see the area it covers. It has templates for spheres, cubes, cuboids and cones.
--
Outside of this it might be useful to remember that any "grids" or such battle maps are just "representations" only. The grids/hexes and how cones/etc work on them is only designed as a quick reference not really to be overly specific. It's up to you, the DM, to determine how well a cone/effect/whatever would apply to that situation and any outcome of it - which may include effects beyond the spell like damaging weak structures, altering guards, setting things on fire accidentally, or freezing waters or making a damp surface slippery for cold blasts. The DMG includes how AoEs work and includes tips for using on a grid. However, if you feel that it is not the best way to use the spell then change it. A spell works how you want it to, at the end of the day.
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Click ✨ HERE ✨ For My Youtube Videos featuring Guides, Tips & Tricks for using D&D Beyond. Need help with Homebrew? Check out ✨ thisFAQ/Guide thread ✨ by IamSposta.
Playing on Roll20 so not an option for irl effects, sadly.
If you're playing on Roll20, you could just draw or import a triangular area with the correct size/angle and rotate it to cover the desired area. No need to constrain yourself to 45 degree increments, then. :D
Do bear in mind, tho, that if doing this, a square needs to be at least 50% covered to be affected, and it might not be trivial to determine this for some angles, depending on your math chops. In those cases, have the DM adjudicate it, making sure the total number of squares covered is L(L+1)/2, where L = length/5 (that is, L = length, in squares, of the cone). For example, a 15' cone: 15' = 3 squares, total number of squares is 3(3+1)/2 = 3*4/2 = 6; 30' cone: 30' = 6 squares, total number of squares = 6(6+1)/2 = 6*7/2 = 21 squares.
The diameter of the base of the cone should be equal to the height of the cone so the circles (from above) should have a diameter equal to the cone length, not a radius of the cone length.
DMG states:
You select a sphere's point of origin, and the sphere extends outward from that point. The sphere's size is expressed as a radius in feet that extends from the point.
A cone extends in a direction you choose from its point of origin. A cone's width at a given point along its length is equal to that point's distance from the point of origin. A cone's area of effect specifies its maximum length.
As I understand it, a 10ft Sphere has a Radius of 10ft measured from an intersection, thus will cover any square that is at least 50% covered by the effect of the spell. Also a Cone will extend up to the specified range and at any point, it's width matches it's length. Thus 5ft away from the point of origin it is 5ft wide, 10ft away is 10ft wide and so on till you reach the max cone range.
My problem is... Which would be the correct 15ft diagonal cone... The one on the left or the one on the right? On a grid, neither really reaches out 15ft away from the caster, because Pitagoras doesn't apply to fantasy grid worlds apparently.
Are you saying the circles represent spheres? Because I thought the whole graphic was for cones from different angles (the circles being cones fired from above).
Cones don't work well on a grid. You could follow the rules in the book (XGtE has more explanations for area of effects on a grid), or you could use 1/6 of a circle as the area for maximum accuracy.
Cones on the left are more accurate for "real world" representations, but the cones on the right are what is commonly agreed upon for tabletops.
One thing to keep in mind is that the origin point is usually not placed on a cross-section of squares. Place the origin in the singular square that the effect is going to spread outward from. That square counts as the first 5 feet, and you can more easily determine the rest of the area by expanding outward.
It's certainly not the only way to handle AoEs, but it is the easiest and most commonly accepted method.
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You don't know what fear is until you've witnessed a drunk bird divebombing you while carrying a screaming Kobold throwing fire anywhere and everywhere.
Cones on the left are more accurate for "real world" representations, but the cones on the right are what is commonly agreed upon for tabletops.
One thing to keep in mind is that the origin point is usually not placed on a cross-section of squares. Place the origin in the singular square that the effect is going to spread outward from. That square counts as the first 5 feet, and you can more easily determine the rest of the area by expanding outward.
It's certainly not the only way to handle AoEs, but it is the easiest and most commonly accepted method.
Cones on the left are more accurate for "real world" representations, but the cones on the right are what is commonly agreed upon for tabletops.
One thing to keep in mind is that the origin point is usually not placed on a cross-section of squares. Place the origin in the singular square that the effect is going to spread outward from. That square counts as the first 5 feet, and you can more easily determine the rest of the area by expanding outward.
It's certainly not the only way to handle AoEs, but it is the easiest and most commonly accepted method.
The corner thing is in the 5e rules.
I said "usually". The "corner thing" mostly relates to cone/line spells that originate from the caster. Ignoring it on a grid results in exactly the same thing with (typically) less confusion.
When you cast a spell with an origin on a corner, the corner is not included in the AoE (line/cone), and you start counting distance from the origin. The first square adjacent to the origin is the first 5ft.
If you instead just consider that first square to be both the origin and first 5ft of the effect then it's easier for people to understand the total area. This doesn't change the total area/distance or the squares affected, so whatever method works for the individuals at the table. 👌
You don't know what fear is until you've witnessed a drunk bird divebombing you while carrying a screaming Kobold throwing fire anywhere and everywhere.
Cones on the left are more accurate for "real world" representations, but the cones on the right are what is commonly agreed upon for tabletops.
One thing to keep in mind is that the origin point is usually not placed on a cross-section of squares. Place the origin in the singular square that the effect is going to spread outward from. That square counts as the first 5 feet, and you can more easily determine the rest of the area by expanding outward.
It's certainly not the only way to handle AoEs, but it is the easiest and most commonly accepted method.
The corner thing is in the 5e rules.
I said "usually". The "corner thing" mostly relates to cone/line spells that originate from the caster. Ignoring it on a grid results in exactly the same thing with (typically) less confusion.
When you cast a spell with an origin on a corner, the corner is not included in the AoE (line/cone), and you start counting distance from the origin. The first square adjacent to the origin is the first 5ft.
If you instead just consider that first square to be both the origin and first 5ft of the effect then it's easier for people to understand the total area. This doesn't change the total area/distance or the squares affected, so whatever method works for the individuals at the table. 👌
Honestly, the origin square is another topic alltogether. I assume it is the square the caster occupies, as the rules state, that the origin square is not affected, unless caster chooses it to be. And the intersection point I think, is meant to be more of a "from my square I point my hand in that direction" kind of thing.
Right. The Cone extends in a width equal to its length. So a 15' cone would create a circle 15' across. This makes the diameter of your sphere (well, circle) attack 15' and your radius (being half the diameter) 7.5 feet.
Right. The Cone extends in a width equal to its length. So a 15' cone would create a circle 15' across. This makes the diameter of your sphere (well, circle) attack 15' and your radius (being half the diameter) 7.5 feet.
That is a hell of a necro... And wrong info. 15' cone is 15' long, not 7.5'. And at any point it is as wide as it is long.
Right. The Cone extends in a width equal to its length. So a 15' cone would create a circle 15' across. This makes the diameter of your sphere (well, circle) attack 15' and your radius (being half the diameter) 7.5 feet.
That is a hell of a necro... And wrong info. 15' cone is 15' long, not 7.5'. And at any point it is as wide as it is long.
Largely because of the necro its hard to tell what he's actually responding to, but I'm guessing he means for a cone directed downward at targets. This would result in a circle 15' across, or 7.5' radius.
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I am aware, it was asked numerous times, but I am not too convinced about the cone spells.
As per RAW a cone of 15 ft reaches out as far as the range says. And people usually present it as hmm... Better with a picture.
The 15 ft in the middle, diagonally. People present the cones as the one on the right, but shouldn't it be more like the one on the left?
Use a hex map ;)
"Sooner or later, your Players are going to smash your railroad into a sandbox."
-Vedexent
"real life is a super high CR."
-OboeLauren
"............anybody got any potatoes? We could drop a potato in each hole an' see which ones get viciously mauled by horrible monsters?"
-Ilyara Thundertale
I bought the Arcknight spell effects. They’re great for answering AoE questions quickly and easily!
They're slightly expensive, but they’re worth it to me.
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The rule books quite specifically do not go into exactly how the various spells and other area effects must map onto the squares/hexes of a grid. You are free as a DM or table to choose the method(s) that work best for you. The important thing is that it feel balanced and is applied consistently - so enemy creatures and spells use the same method/template.
The diameter of the base of the cone should be equal to the height of the cone so the circles (from above) should have a diameter equal to the cone length, not a radius of the cone length.
Table is using square grid. No can't do.
Playing on Roll20 so not an option for irl effects, sadly.
DMG states:
As I understand it, a 10ft Sphere has a Radius of 10ft measured from an intersection, thus will cover any square that is at least 50% covered by the effect of the spell. Also a Cone will extend up to the specified range and at any point, it's width matches it's length. Thus 5ft away from the point of origin it is 5ft wide, 10ft away is 10ft wide and so on till you reach the max cone range.
My problem is... Which would be the correct 15ft diagonal cone... The one on the left or the one on the right? On a grid, neither really reaches out 15ft away from the caster, because Pitagoras doesn't apply to fantasy grid worlds apparently.
Right seems more accurate. At least, it's "conish" shaped.
"Sooner or later, your Players are going to smash your railroad into a sandbox."
-Vedexent
"real life is a super high CR."
-OboeLauren
"............anybody got any potatoes? We could drop a potato in each hole an' see which ones get viciously mauled by horrible monsters?"
-Ilyara Thundertale
Left would be more accurate since the width of the cone at the end should be the same as the distance. Right feels more accurate, but is wider than it should be as it's a 90 degree cone instead of roughly 60 degree. Both cover the correct number of squares though so use whichever you like as long as you're consistent.
You stated you're on Roll20. Roll20 has the option to use hexes instead of square grids.
You can buy a spell templates pack on Roll20 for about $5 which lets you use transparent overlays to just drag and drop onto your map and see the area it covers. It has templates for spheres, cubes, cuboids and cones.
--
Outside of this it might be useful to remember that any "grids" or such battle maps are just "representations" only. The grids/hexes and how cones/etc work on them is only designed as a quick reference not really to be overly specific. It's up to you, the DM, to determine how well a cone/effect/whatever would apply to that situation and any outcome of it - which may include effects beyond the spell like damaging weak structures, altering guards, setting things on fire accidentally, or freezing waters or making a damp surface slippery for cold blasts. The DMG includes how AoEs work and includes tips for using on a grid. However, if you feel that it is not the best way to use the spell then change it. A spell works how you want it to, at the end of the day.
Click ✨ HERE ✨ For My Youtube Videos featuring Guides, Tips & Tricks for using D&D Beyond.
Need help with Homebrew? Check out ✨ this FAQ/Guide thread ✨ by IamSposta.
If you're playing on Roll20, you could just draw or import a triangular area with the correct size/angle and rotate it to cover the desired area. No need to constrain yourself to 45 degree increments, then. :D
Do bear in mind, tho, that if doing this, a square needs to be at least 50% covered to be affected, and it might not be trivial to determine this for some angles, depending on your math chops. In those cases, have the DM adjudicate it, making sure the total number of squares covered is L(L+1)/2, where L = length/5 (that is, L = length, in squares, of the cone). For example, a 15' cone: 15' = 3 squares, total number of squares is 3(3+1)/2 = 3*4/2 = 6; 30' cone: 30' = 6 squares, total number of squares = 6(6+1)/2 = 6*7/2 = 21 squares.
Are you saying the circles represent spheres? Because I thought the whole graphic was for cones from different angles (the circles being cones fired from above).
Cones don't work well on a grid. You could follow the rules in the book (XGtE has more explanations for area of effects on a grid), or you could use 1/6 of a circle as the area for maximum accuracy.
Cones on the left are more accurate for "real world" representations, but the cones on the right are what is commonly agreed upon for tabletops.
One thing to keep in mind is that the origin point is usually not placed on a cross-section of squares. Place the origin in the singular square that the effect is going to spread outward from. That square counts as the first 5 feet, and you can more easily determine the rest of the area by expanding outward.
It's certainly not the only way to handle AoEs, but it is the easiest and most commonly accepted method.
You don't know what fear is until you've witnessed a drunk bird divebombing you while carrying a screaming Kobold throwing fire anywhere and everywhere.
The corner thing is in the 5e rules.
I said "usually". The "corner thing" mostly relates to cone/line spells that originate from the caster. Ignoring it on a grid results in exactly the same thing with (typically) less confusion.
When you cast a spell with an origin on a corner, the corner is not included in the AoE (line/cone), and you start counting distance from the origin. The first square adjacent to the origin is the first 5ft.
If you instead just consider that first square to be both the origin and first 5ft of the effect then it's easier for people to understand the total area. This doesn't change the total area/distance or the squares affected, so whatever method works for the individuals at the table. 👌
You don't know what fear is until you've witnessed a drunk bird divebombing you while carrying a screaming Kobold throwing fire anywhere and everywhere.
Honestly, the origin square is another topic alltogether. I assume it is the square the caster occupies, as the rules state, that the origin square is not affected, unless caster chooses it to be. And the intersection point I think, is meant to be more of a "from my square I point my hand in that direction" kind of thing.
Right. The Cone extends in a width equal to its length. So a 15' cone would create a circle 15' across. This makes the diameter of your sphere (well, circle) attack 15' and your radius (being half the diameter) 7.5 feet.
That is a hell of a necro... And wrong info. 15' cone is 15' long, not 7.5'. And at any point it is as wide as it is long.
Right. Total width aka diameter. making your radius half that. cause thats what those words mean.
(i used a wish spell?)
For a 15' Sphere that would be correct. But a 15' Cone has a radius of 15'.
Largely because of the necro its hard to tell what he's actually responding to, but I'm guessing he means for a cone directed downward at targets. This would result in a circle 15' across, or 7.5' radius.