This website is currently in development. It is not yet content-complete and may contain minor errors. See the older online rules reference for referee-facing material, to be added here soon.

Return to the roots of fantasy adventure! Don your chain mail, grab your iron spikes, and prepare your magic missile. Glory, wonder, and doom await!

• This website is a free-to-use, basic version of Old-School Essentials (OSE), consisting of the complete game rules and a reduced selection of classes, options, equipment, spells, monsters, and magic items. See below for more details on the full Old-School Essentials game.
• Simple rules let imagination and fast-paced action take the spotlight.
• Clear, modern presentation makes the game easy to learn and quick to reference.
• 100% compatible with the 1980s D&D rules and with decades of classic adventures and supplements.

Rules only: Note that this website is a rules reference only. Introductory material and examples of play present in the full game are not included in this website.

Old-School Essentials consists of a pair of lavishly illustrated core books, available in print and PDF from https://ose-rpg.com:

The Old-School Essentials Player's Book: The complete player's guide to OSE, including reams of additional content not present in this website:

• More character options: More classes: acrobat, assassin, barbarian, bard, cleric, druid, fighter, illusionist, knight, magic-user, paladin, ranger, thief. More fantasy races: drow, duergar, dwarf, elf, gnome, half-elf, halfling, half-orc, human, svirfneblin.
• More customisation options: Create a character by choosing class and race separately (e.g. an elf knight or a halfling thief). Customise your character with weapon proficiencies, secondary skills, and more.
• More spells: 34 druid spells and 72 illusionist spells.
• More items: Including poisons and dogs.
• More optional rules: Dozens of extra options to tweak the game to your preferences.
• Full introduction: Introducing the game, common terminology, the most commonly used rules, and the ecosystem of cross-compatible old-school games.
• Copious play examples: Including 13 full-page examples.
• Full indexes: Indexes of rules topics, spells, and tables.

The Old-School Essentials Referee's Book: The complete referee's guide to OSE, including reams of additional content not present in this website:

• More monsters: 120 extra monsters, including mimics, piercers, shambling mounds, banshees, coffer wights, terrible eyes, metallic dragons, liches, drow, deep ones, the terrifying tarrasque and many more classic monsters.
• More magic items: 150 additional magic items, including the apparatus of the crab, ioun stones, figurines of wondrous power, the deck of many things, vorpal blades, dancing swords, the mighty holy avenger, and many more.
• Copious play examples: Including a 7-page example of creating a small setting, base town, and starting dungeon.
• Full indexes: Indexes of monsters, magic items, and tables.

We encourage Old-School Essentials fans to create their own adventures and rules supplements! Our third-party license explains how to do this. See https://necroticgnome.com/pages/publishing-for-old-school-essentials.

All content in this website © 2026 Necrotic Gnome. Old-School Essentials™ and all related characters and elements © 2026 Necrotic Gnome. All Rights Reserved. The material in this website is not open content and may not be copied, adapted, or remixed without permission from Necrotic Gnome.

This work includes material taken from the System Reference Document 5.1 (“SRD 5.1”) by Wizards of the Coast LLC and available at https://dnd.wizards.com/resources/systems-reference-document. The SRD 5.1 is licensed under the Creative Commons Attribution 4.0 International License available at https://creativecommons.org/licenses/by/4.0/legalcode. Necrotic Gnome is not affiliated with Wizards of the Coast, holder of the Dungeons & Dragons trademark.