Area Effects

An area effect originates from a single square or creature. Unless otherwise stated, an area effect affects [Flying], [Swimming], and [Burrowing] creatures the same way it affects creatures without those conditions. Unless otherwise stated, multiple instances of an area effect affect those within them separately. For example, if two effects each deal damage to all within a created spread, creatures that happen to be within the spreads created by both effects would take damage from both effects.

Spreads

Spreads expand evenly in all directions. If a spread originates from a square, its radius is measured from a vertex of that square. (The source of the effect that creates the spread chooses the vertex.) If a spread originates from a creature, its radius is measured from each edge of each square that creature occupies, and its area includes each square within any of these measurements. (A spread that originates from a creature that occupies more than one square is larger than an identical spread originating from a creature that occupies only a single square.)

Wedges

Wedges expand from a vertex of a square in a quarter-circle out to their given length. If a wedge originates from a square, the source of the effect chooses a vertex of that square. If a wedge originates from a creature, the source of the effect chooses a square that creature occupies and chooses a vertex of that square. A wedge can point in any of eight directions when drawn on a grid (up and down, sideways, and diagonally).

Lines

Lines extend in a given direction. This direction is chosen by the source of the effect, unless otherwise stated. If a line originates from a square, it extends from that square. If a line originates from a creature, it extends from a square that creature occupies (the source of the effect chooses this square). Unless otherwise stated, a line is 5 ft wide.