2012 · 资料书（用于增强玩法的规则/选项）
On the Inverse Calculus of Unseen Refraction
This gothic magical accessory explores invisibility as both an arcane science and a source of psychological unease, examining the effects of existing unseen and questioning the boundary between illusion and reality. It provides background and rules for alchemical and optical experimentation, including six alchemical discoveries, a metamagic feat, and eight spells and alchemical formulae such as the Transparency Mutagen and vitrific visibility. Designed for campaigns involving alchemy, magic, mad science, or Gothic adventure themes.
技能型（购买或获得技能）基于属性/数值（STR、CON、PER 等）等级制（获得经验值并升级）
免费，支持网页、Android 和 iOS
用 Ludoya 玩 On the Inverse Calculus of Unseen Refraction
游戏信息（人数、游戏时长、年龄、制作人员）来自 BoardGameGeek。