Voidfall · Board game rules
Does attacked sector count with Advanced Deep Space Missiles defense?
Quick answer
No — the Combat sector itself is never counted; only other sectors you control that are adjacent to the invaded sector and contain a Starbase or Shipyard count for Improved Deep Space Missiles.
Details
Improved Deep Space Missiles deals damage based on how many different sectors with a Starbase or Shipyard are adjacent to the invaded sector — for the Defender, "each of the Invader's Carrier Fleet Powers..." wait, more precisely: the Defender deals 1 or 2 Damage if they have "one or more different sectors with a Starbase or Shipyard adjacent to the invaded sector" [p.35 — Approach step]. The same wording applies to the Invader's version, counting sectors adjacent to the Combat sector [p.36 — Salvo step].
Since the ability explicitly requires the qualifying sector to be adjacent to the invaded/Combat sector, the invaded sector itself cannot be counted — a sector is not considered adjacent to itself. Only separate sectors you control, bordering the Combat sector hex-to-hex, and containing a Starbase or Shipyard, are tallied for this bonus [p.18 — Guilds and Installations] [p.35 — Approach step].
Watch out: Remember that Voidstorm tokens break adjacency entirely [p.18 — Sector adjacency and Voidstorms], so a sector that would otherwise be adjacent to the Combat sector does not count if a Voidstorm sits between them.