The notebook lets you draw and erase notes while you play. The 0.1.7 patch notes list a notebook crash fix. See Notes for the note letters.
Sources and community notes
- The 0.1.7 patch notes (June 24, 2024) include a fix for a notebook crash and mention drawing and erasing in the notebook.
- A strategy guide recommends writing potion effects into the in-game notebook (N) so you can check them without leaving the game.
Community-sourced (added October 2026, not yet verified in-game). Sources: Steam patch notes 0.1.7 (June 24, 2024); Steam guide: How easly win almost all your runs by GettyX.
From the official manual
- The manual devotes a page to the notebook: because memory is unreliable, especially while asleep, it advises making notes of your discoveries, and says the notebook can be used at any time during a run.
From the game's official manual. Unlike the rest of the notes on this page, this is a primary source: it is the developer's own documentation, not community research.