Area Templates & Spell Templates

Onyx · Aug 14, 2006

The chart in the back of the DMG shows us that a 20ft radius looks something like this on a grid.

If we read our DMG (pg 34) it tells us that when using a grid we choose an intersection between squares and count off the radius from that point, then draw a circle... if any square is mostly covered (ie over 50%) then it is affected.

So, instead of what is shown as the commonly accept template, we should have one that looks like this
(forgive the use of MSPaint)

Does anyone have any light they can shed on this matter?

Infiniti2000 · Aug 14, 2006

Onyx said:
If we read our DMG (pg 34) it tells us that when using a grid we choose an intersection between squares and count off the radius from that point, then draw a circle... if any square is mostly covered (ie over 50%) then it is affected.

I just read my DMG and it says nothing of the sort.

The PH pg. 175, however, says this, as I quote from the SRD:

SRD said:
Area
Some spells affect an area. Sometimes a spell description specifies a specially defined area, but usually an area falls into one of the categories defined below.

Regardless of the shape of the area, you select the point where the spell originates, but otherwise you don’t control which creatures or objects the spell affects. The point of origin of a spell is always a grid intersection. When determining whether a given creature is within the area of a spell, count out the distance from the point of origin in squares just as you do when moving a character or when determining the range for a ranged attack. The only difference is that instead of counting from the center of one square to the center of the next, you count from intersection to intersection.

You can count diagonally across a square, but remember that every second diagonal counts as 2 squares of distance. If the far edge of a square is within the spell’s area, anything within that square is within the spell’s area. If the spell’s area only touches the near edge of a square, however, anything within that square is unaffected by the spell.

Hopefully, the underlined portion is all the light you need.

zypherillius · Aug 14, 2006

probably wont be of much help

this probably wont help much, but i think the guy inside the 20 foot rad aoe is going to have a bad day if the troll goes before he in initative order.

Onyx · Aug 14, 2006

Not Quite

I misquoted the DMG I'm afraid, I was refering to pg 28 under 'Area Spells'.

"To employ the spell using a grid, the caster needs to designate an intersection of two lines on the grid as the center of the effect. From that intersection, it's easy to measure a radius using the scale on the grid. If you were to draw a circle using the measurements on the grid, with the chosen intersection at the center, then if the majority of a grid square lies within that circle, the square is a part of the spell's area."

To the point of counting our diagonals, if we are counting from an intersection of two lines on a grid, we must follow the idea of the first square being 5', the second being 10' and so on. This was originally a rule devised to account for the fact that diagonals actually are longer than straight shots on a grid.

The arguement that a circular effect, such as a fireball, should encompass the entirety of a circle on a grid seems potent to me.

Thus, my arguement that the following must be the correct shape.

Gumby · Aug 14, 2006

I've seen the first diagram in a few WotC products. It's the official one, regardless of how they say it should be constructed. However, my group uses the second, because it's rounder and simply looks like a better depiction of a fireball's area.

kreynolds · Aug 14, 2006

While the PHB seems to favor simplicity, therefore a smaller area for a 20-foot fireball, I think the DMG favors the larger area, despite the diagram at the back. The part that convinces me of the DMG favoring a larger area is "if the majority of a grid square lies within that circle, the square is a part of the spell's area". Based on the attached picture, I'd say the larger area is in order.

Infiniti2000 · Aug 14, 2006

Onyx said:
The arguement that a circular effect, such as a fireball, should encompass the entirety of a circle on a grid seems potent to me.

Perhaps, but the D&D-movement choice is reasonable and is not in error.

Onyx said:
Thus, my arguement that the following must be the correct shape.

Incorrect by the rule I quoted. The attached file is how you count it and shows why those 8 squares you want added are not added in.

Feel free to change the rule to add those 8 squares. The overlay of the circle on the grid seems to support it as a valid estimation.