2007 · 资料书（用于增强玩法的规则/选项）
Hollow Earth Expedition Addendum
This supplement expands the pulp adventure roleplaying game with additional material for explorers and other characters. It provides further details on Talents, Flaws, and equipment that are only briefly covered in the core rulebook.
技能型（购买或获得技能）基于点数（分配点数以获得技能、能力等）骰子（主要为d2/硬币）
免费，支持网页、Android 和 iOS
用 Ludoya 玩 Hollow Earth Expedition Addendum
游戏信息（人数、游戏时长、年龄、制作人员）来自 BoardGameGeek。