S.T.A.L.K.E.R. The Board Game · Board game rules
Can I attack through impassable terrain?
Quick answer
Yes — Impassable Terrain blocks Movement, but Entities can still draw Line of Sight and measure Range through it, so Attacks are possible.
Details
Impassable Terrain is one of the five space-edge types: Entities can't Move through it, but they can draw a LoS and measure Range through it [p.12 — SPACE EDGES]. Since Attacks generally require the target to be within Range and/or in LoS (either Weapon Max. Range + LoS, or whatever Range/LoS the specific Attack states), an Attack across an edge of Impassable Terrain is valid as long as those Range/LoS conditions are met [p.27 — STALKER ATTACK].
This is different from a Wall, which blocks Movement, LoS, and Range entirely, making the two spaces not even adjacent [p.12 — SPACE EDGES]. Water spaces are a specific example of Impassable Terrain — Entities can't enter or move through them, but they can still see and measure Range across the water [p.12 — Spaces with water; p.41 — Water space].
Watch out: Don't confuse Impassable Terrain with a Wall — both stop Movement, but only a Wall also blocks LoS and Range, which would prevent an Attack entirely [p.12 — SPACE EDGES].