The Necroplasmic Beacon is a craftable post-Moon Lord item used to summon the Polterghast boss in the Dungeon. It is not consumed upon use; therefore, it can be used as many times as the player desires. Note that, if the Polterghast has not been defeated yet, the boss can also be summoned by slaying 30 Phantom Spirits in the Dungeon.
Attempting to use the item while the player is not in the Dungeon, Polterghast is alive, or using it in a world that has no bosses defeated will cause it to do nothing.
- Its sprite resembles the torch seen on the logo of Darkest Dungeon.