5 foot-radius sphere centered on a point within range, which one is correct?

5 thoughts on “5 foot-radius sphere centered on a point within range, which one is correct?

  1. Yunei says:

    Maybe there’s something I’m missing and I’ll sound silly for asking this but… I’ve played plenty of RP games (D&D etc.) and I’ve never seen movement, character placement, or any form of targeting actually use line intersections instead of the center of a square/hex. I’m sure “mathematically” the left (red) circle is distance accurate, that being said, the right (blue) circle is showing accurate target placement for the game. it’s obvious this question comes about from a player or DM wanting to know “just how squares does this 5 or 10 or 15 ft radius affect?” I’ve been looking for references on this for a game I’m in where these kind of arguments seem to happen quite often and I’m not finding any images that give a clear and correct answer.

    For example, could you please illustrate the area of effect for “Earth Tremor” (D&D 5e, lvl 1 evocation, range: self, 10 ft radius)? And please don’t draw it with the origin on a line intersection because that’s not where the character is standing.

  2. David Ellsworth says:

    My suggestion is to then use templates. Remember at least 1/2 the square needs to be within the target area. If you use a 5’radius from the center of a square not a single additional square would be affected. (none of the surrounding squares would be half or more contained within the 5′ radius). Nothing is perfect.

  3. It also bears considering that, as exampled in some other responses to similar questions in later years (as these responses are from 2016), the range on the right is cited as “correct” for, say, the Thunderclap cantrip radius-effect (caster is the center, each adjacent/diagonal square is at least sufficiently affected via the “at least half” consideration that has been consistent in 5E). This is why some people have very legitimate confusion as to the range/area of a “5′ radius” spell. The applied truth is that technically *both* are correct relative to the rules/SA — it just depends on the “rounding” of being on a line or at the center of a square from a game mechanic POV. It’s just a question of the character’s POV being “good enough” (via a Spell Attack roll, if applicable, and *character* LOS vs the *player’s* “above it all” overview of the the grid/map in question) to hit a given “sweet spot” for optimal effect. As with most things in that regard, that’s where DM judgement come into play….

  4. Here’s how I see it and am going to work it: The spell doesn’t originate from the crown of your head, or your center of mass.
    It originates from one of your hands. You gesture with that hand away form your body – right above one corner of the square you’re standing on.

    Player has the choice of which corner his hand is over. Is he covering 1/4 of the area of effect? Yes. Does that stink? Yes. It is fair? yes.

    If the spell isn’t an area around the caster, then great, they just cast it to an origin point at a juncture of their choice. Righteous.


  5. John Powers says:

    A point of contention is the difference reading the grid rules in the DMG and the theater of the mind rules. In the grid rules, it says the spell must be targeted at the intersection of grid squares or hexes. What does “intersection” mean? Does it mean the vertex points on the corners? If so, then Mearls is correct.

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