All ranged and melee attacks can only be performed against enemies within line-of-sight, which means that a line can be drawn from any corner of the attacker’s hex to any corner of the defender’s hex without touching any part of a wall.

Obstacles and characters do not block line of site, only walls block line-of-sight,

A wall is the line edge of a map tile or the entire area of any partial hex along the edge of a map tile, unless covered by an overlay tile.

Note: Two hexes separated by a wall line are not considered adjacent, and range cannot be counted through walls.