Line [Area of Effect]
Source: Player’s Handbook (2024) p. 370. Available in the SRD and the Free Rules (2024)
A Line is an area of effect that extends from a point of origin in a straight path along its length and covers an area defined by its width. The effect that creates a Line specifies its length and width.
A Line’s point of origin isn’t included in the area of effect unless its creator decides otherwise.