Cone-Shape

Cone, Cylinder, Line, or Sphere: Most spells that affect an area have a particular shape, such as a cone, cylinder, line, or sphere.

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.

see above를 따라가면

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, even 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 sphere]]], 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.

즉 폭발형의 일반적인 형태는 구, 원이 아니군. 그럼 cone-shape에서 quarter-circle in the direction 라는 것은 1/4의 구, 말그대로 원뿔형
이라는 것 아닌가?

2차원적이라면 cone-shape 가 아니라 fanlike 이라고 했겠지. Sphere 가 아니라 circle 이라고 했을테고.