[PF] Radius spells in 3 dimensions?

[jaybird]

Just a quick rules question - can I aim a Fireball up to have it airburst and have a blast of less then 20 feet radius on the ground? Poor man's Shape Spell, so to speak. My DM says I can't, and I haven't been able to find something that contradicts him, even though that ruling seems oddly nonsensical, even for D&D.

[Viktyr Gehrig]

It isn't legal by RAW, but-- and I say this as a DM who thinks most players are way too entitled-- any DM who doesn't allow it to work is an idiot.

[LansXero]

Doesnt fireball specifically describe a bead that explodes on contact with a surface though?

[Anxe]

Looking at the SRD, you can aim the spell to detonate at any distance and height. Area description describes the default area as a sphere, not a circle. By RAW, you should be able to "reduce" the area as you have described. However, your DM is allowed to change that. Just remind him that it goes both ways for his NPCs.

[Bhaakon]

Doesnt fireball specifically describe a bead that explodes on contact with a surface though?

The bead does explode if it hits a surface before reaching its target point, but it doesn't need impact a surface to explode. From the PFSRD (http://www.d20pfsrd.com/magic/all-spells/f/fireball):


You point your finger and determine the range (distance and height [emphasis added]) at which the fireball is to burst.

So you can select a target height for your fireball and it doesn't need to impact a surface to go off. It seems cut and dried to me: air burst fireballs are specifically allowed in pathfinder RAW, though their mechanical effects are not described.

[Fax Celestis]

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.1 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.

Burst, Emanation, or Spread

Most spells that affect an area function as a burst, an emanation, or a spread. In each case, you select the spell's point of origin and measure its effect from that point.

A burst spell affects whatever it catches in its area, including creatures that you can't see. It can't affect creatures with total cover from its point of origin (in other words, its effects don't extend around corners). The default shape for a burst effect is a sphere2, but some burst spells are specifically described as cone-shaped. a burst's area defines how far from the point of origin the spell's effect extends.

An emanation spell functions like a burst spell, except that the effect continues to radiate from the point of origin for the duration of the spell. Most emanations are cones or spheres.

A spread spell extends out like a burst but can turn corners. You select the point of origin, and the spell spreads out a given distance in all directions. Figure the area the spell effect fills by taking into account any turns the spell effect takes.

Cone, Cylinder, Line, or Sphere

Most spells that affect an area have a particular shape.

A cone-shaped spell shoots away from you in a quarter-circle in the direction you designate. It starts from any corner of your square and widens out as it goes. Most cones are either bursts or emanations (see above), and thus won't go around corners.

When casting a cylinder-shaped spell, you select the spell's point of origin. This point is the center of a horizontal circle, and the spell shoots down from the circle, filling a cylinder. A cylinder-shaped spell ignores any obstructions within its area.

A line-shaped spell shoots away from you in a line in the direction you designate. It starts from any corner of your square and extends to the limit of its range or until it strikes a barrier that blocks line of effect. A line-shaped spell affects all creatures in squares through which the line passes.

A sphere-shaped spell expands from its point of origin to fill a spherical area. Spheres may be bursts, emanations, or spreads.


Fireball

School evocation [fire]; Level magus 3, sorcerer/wizard 3; Domain fire 3
CASTING
Casting Time 1 standard action
Components V, S, M (a ball of bat guano and sulfur)
EFFECT
Range long (400 ft. + 40 ft./level)
Area 20-ft.-radius spread
Duration instantaneous
Saving Throw Reflex half; Spell Resistance yes

DESCRIPTION

A fireball spell generates a searing explosion of flame that detonates with a low roar and deals 1d6 points of fire damage per caster level (maximum 10d6) to every creature within the area. Unattended objects also take this damage. The explosion creates almost no pressure.

You point your finger and determine the range (distance and height) at which the fireball is to burst.3 A glowing, pea-sized bead streaks from the pointing digit and, unless it impacts upon a material body or solid barrier prior to attaining the prescribed range, blossoms into the fireball at that point. An early impact results in an early detonation. If you attempt to send the bead through a narrow passage, such as through an arrow slit, you must "hit" the opening with a ranged touch attack, or else the bead strikes the barrier and detonates prematurely.

The fireball sets fire to combustibles and damages objects in the area. It can melt metals with low melting points, such as lead, gold, copper, silver, and bronze. If the damage caused to an interposing barrier shatters or breaks through it, the fireball may continue beyond the barrier if the area permits; otherwise it stops at the barrier just as any other spell effect does.

1 Remember, D&D's grids are three-dimensional. See Air Combat and maneuverability.
2 A three-dimensional object.
3 If you can't do what you're saying, why do you get to determine the height at which the spell goes off?

[Trinoya]

You totally can aim a fireball to do that, it's fairly effortless to (although I require a simple concentration check to illustrate the point that you're choosing a 'spot' rather than a target).

That said: A lot of people forget the combat is in three dimensions. It can get really fun taking an AoO because someone FELL through a threatened square.

[Daftendirekt]

Yeah, most DMs forget that D&D is 3-dimensional if there isn't a dragonborn/raptoran in the game, but you can do exactly that. I actually had a geometer wizard once, and with his 20+ int and math skills I was able to justify that he knew precisely where to aim his fireball to hit enemies but not allies. Sure, I could have spent five minutes counting out squares on the battlemat and such, but that's too much time wasted during combat.

[El Dorado]

It's completely within the scope of the rules. Great for fighting giants and huge dragons when your party are in melee.

[Infernalbargain]

1 Remember, D&D's grids are three-dimensional. See Air Combat and maneuverability.
2 A three-dimensional object.
3 If you can't do what you're saying, why do you get to determine the height at which the spell goes off?

To get super nitpicky, a sphere is a two dimensional that is embedded in three dimensional space, whereas a ball is the analogous three dimensional object. So technically fireball only hits things on the edge of its radius.

[georgie_leech]

As a DM, I'd argue you'd need to make an intelligence roll to determine where you'd need to aim, with the possibility of getting it wrong. After all, if you can't muck around with height, it denies any epic aeriel battle sequences, and who doesn't love a good battle of flying legends?

[jaybird]

As a DM, I'd argue you'd need to make an intelligence roll to determine where you'd need to aim, with the possibility of getting it wrong. After all, if you can't muck around with height, it denies any epic aeriel battle sequences, and who doesn't love a good battle of flying legends?

I think I'll propose this to my DM next time the issue comes up, thanks. Not that it has anything to do with me playing a Wizard or anything :smallwink: