Skullboy's Illustrated Guide to Demons is an art book and gaming aid.
I am drawing my interpretation of all of the new demons presented in the OSE Demonic Grimoire and making them into an artbook that you can use to show your players at the table, or to just inspire you while writing your own campaign! Rest assured I will make them COLORFUL, WEIRD and CARTOONISH.
Content Warning: This book will feature some adult content, demonic nudity and rude language.
The final product will be both a book and a set of downloadable spot illustrations so you can easily isolate and use the individual pieces when revealing the demons to your players.
It will include:
Images of the new Demon Lords!
Images of the denizens of their Hells!
Images of their Clerics!
This is just a taste! The final book will detail all 8 of the new Demon Lords and their various minions!
This book will be at a minimum 24 fully illustrated pages (depending on stretch goals it could be more) and will be 7x9 inches (US Trade Large) I find this book size to be extremely satisfying. It's got just a little more wiggle room than A5, and I think it helps the art pop and the work breathe.
SAVE BIG with DISCOUNTED GROUP SHIPPING! Thirteen of the seventeen projects in OSE Month are participating in group shipping with Demonic Grimoire. This means all rewards from these projects will be grouped and shipped together so that you can back multiple projects without paying a ton for shipping! For instance, if you're in the US and back the Demonic Grimoire Ritualist Pledge Level + 9 other projects, you are paying up to $29; saving you $124 vs. the approx $153 if you had backed each project individually.
Please note that the values in the table are an estimate to the best of our knowledge at the time the campaign launched given the shipping fees and rates from our fulfillment warehouses. Please see the FAQ section for more information on shipping.
Old-School Essentials Month
Old-School Essentials Month is a group-collab project led by Exalted Funeral and Necrotic Gnome, featuring a new 176-page OSE book — the Demonic Grimoire — and sister projects from 16 other renowned creators in the OSE community.
The theme of OSE Month 2026 is: DEMONS! Get ready for hordes of new monsters, adventures set in the realms of hell, fiendish new character options, and lashings of blood-dripping art.
Group Achievements
We will be announcing a series of achievements tied to the success of all OSE Month projects jointly! To start with:
All projects funded: When all OSE Month projects fund, we will arrange a community Ask Me Anything session on Discord, featuring creators from across the projects. This will be a chance to chat with the OSE Month creators about their projects.
Old-School Essentials (OSE) is a role-playing game of fantastic adventure inspired by classic games of the 1970s and 1980s. Players delve into forsaken ruins, battle fearsome monsters, explore haunted forests and perilous mountain ranges, sail the high seas in search of lost lands, recover fabulous treasures, and unearth secrets of ancient magic.
