Core Rules · AD&D Core Rules 2.0, reborn

A tale from the dragon's hoard

Some campaigns never really end

In 1998, a box arrived with a CD inside and a promise on the cover: every rule of Advanced Dungeons & Dragons in one program. AD&D Core Rules 2.0, and a year later its Expansion, rolled our characters, filled the sheets, built encounters, counted treasure and kept the books a click away. For a whole generation of players it was the closest thing to magic a beige PC could do.

Then the years passed. Windows changed, the installer stopped working, and the discs went to a shelf.

Not long ago I wanted to play AD&D again with my friends. We had grown used to the comforts that D&D Beyond gives the fifth edition: characters made in minutes, sheets that do the math, everything in one place. Second edition deserved the same. And I already owned the original discs of Core Rules 2.0 and the Expansion. I just couldn't use them.

So, with Claude's help, I decided to port it to our times. Not a new program that merely remembers the old one, but the same program: every screen, every table, every roll, reading and writing the very files the original wrote, so a character made in 1999 opens today and a character made today opens in 1999.

Wagner Brahm

A bard on a cliff above a river and a castle, under a stormy sky — The Bard, John Martin, c. 1817

The original application

AD&D Core Rules 2.0 (1998) and its Expansion (1999), the original Windows programs by TSR and Evermore Entertainment. You still need them: the app reads its rules, monsters and books from your own discs.

The box of AD&D Core Rules CD-ROM 2.0, a knight with a glowing sword facing a green dragon — **Core Rules CD-ROM 2.0** · TSR, 1998

The box of AD&D Core Rules 2.0 Expansion, a warrior with an axe facing a red dragon — **Core Rules 2.0 Expansion** · TSR, 1999

The back of the Expansion box, with screenshots of the original program — The back of the Expansion box

The Core Rules 2.0 Expansion CD-ROM — The Expansion CD-ROM

The boxes and disc of the original application. Their artwork belongs to its copyright holders.

The adventure, today

Every screen of the original

Written in Rust, Core Rules runs natively on Linux with GTK 4 and libadwaita, with no Wine, on Windows 11 with WinUI 3 and on the Mac with SwiftUI. It has the Character Generator with Create, Enter and Update Character, kits and Player's Option, the character sheet, parties, the NPC, treasure and encounter generators, Table Rolls, editors for every user database, DM Toolkit packages, the rule books and the help, and imports a whole folder of community add-ons at once.

A module character with his portrait — Characters with their portraits

Import Add-ons listing the Community Add-ons Collection — New: Import Add-ons, a whole folder at once

Rolling ability scores in New Character — New Character, Methods I to VI

Jarlaxle's character sheet — The character sheet, ready to print

The red dragon's picture in the library — Every monster of the discs, with its picture

Building an orc encounter from a template — Encounters from templates

And on Windows 11

The Windows 11 version has every screen of the Linux one, over the same backend and the same files, with the look of a Windows 11 app: the navigation pane, command bars, settings cards, the light, dark and high-contrast themes and the Mica backdrop. The help files of the discs open in the app's own Help page, since Windows 11 no longer reads them. It comes from the Microsoft Store, free, signed and kept up to date by the Store.

A module character with his portrait on Windows 11 — Characters with their portraits

Import Add-ons on Windows 11 — Import Add-ons

Rolling ability scores in New Character on Windows 11 — New Character

Jarlaxle's character sheet on Windows 11 — The character sheet

The red dragon's picture on Windows 11 — Monsters with their pictures

An orc lair encounter on Windows 11 — Encounters from templates

And on the Mac

The macOS version is a native SwiftUI app for Apple Silicon Macs, over the same backend and the same files: the sections, the entries and the details in three columns, every action in the menu bar, and the sheets, the help and the generators in their own windows. Here it is in Portuguese. Download the .dmg.

A module character with his portrait on macOS — Characters with their portraits

Import Add-ons on macOS — Import Add-ons

Jarlaxle's character sheet on macOS — The character sheet

The red dragon's picture on macOS — Monsters with their pictures

An orc lair encounter template on macOS — Encounter templates

Then & now

The same journey, a new road

The flow of every screen follows the original: the same choices, in the same order, giving the same results. On the left, the original program of 1998–1999, captured under Wine for comparison; on the right, the same task in Core Rules.

The original Core Rules 2.0 character screen — **1998.** The original AD&D Core Rules 2.0: the Characters screen, with Create, Update and Enter Character.

The Core Rules character list — **Today.** The character list in Core Rules, reading the same character files.

The original Expansion encounter dialog — **1999.** The original Expansion: an encounter from the "Orc, Wandering" template, with its totals of gold and experience.

The Core Rules New Encounter dialog — **Today.** New Encounter in Core Rules: template, monster type, totals and the monsters it rolled.

**1999.** The original treasure generator: lair types A to I, individual types J to Z, Accumulate Rolls.

The Core Rules treasure roller — **Today.** Roll Treasure in Core Rules, with the same types, the same tables and a summary.

Screenshots of the original AD&D Core Rules 2.0 and Expansion programs are shown only to compare the two; the original program, its interface and artwork belong to their copyright holders.

What's in the tome

Everything the original did, and more

Character Generator

New Character, Enter Character and Update Character, with races, subraces, kits, proficiencies, rogue skills, psionics, spells learned as the rules learn them, and starting equipment.

DM Toolkit

NPC, treasure and encounter generators, encounter templates and frequency tables, traps, Table Rolls, and packages to share with other DMs.

The library

Races, classes, kits, items, spells, psionic powers and monsters, with their pictures and icons, and the Core Rules books in a reader with search.

Import Add-ons

New in 1.2.0: a whole folder of community add-ons in one go, loose or zipped, checked before anything is written, with their pictures and a backup first. The Community Add-ons Collection comes as one .zip for it.

Faithful files

Characters, monsters, encounters and packages made in either program open in the other. Results were compared with files the original wrote.

Linux, Windows 11 and macOS

.deb for Ubuntu, .rpm for Fedora, pacman for Arch, CachyOS and Omarchy, a Flatpak and an AppImage for every other distribution, the Microsoft Store for Windows 11 and a native app for Apple Silicon Macs, in English, Português (Brasil), Español, Italiano, Français and Deutsch.

Ready the horses

Download Core Rules

Version 1.2.0, for Linux, Windows 11 and macOS

Pick the file for your system; each link downloads it directly. The Linux files are for x86-64; Windows 11 comes from the Microsoft Store, and the Mac file is for Apple Silicon.

Ubuntu 26.04 or newer.deb corerules_1.2.0_amd64.deb sudo apt install ./corerules_1.2.0_amd64.deb
Fedora 44 or newer.rpm corerules-1.2.0-1.fc44.x86_64.rpm sudo dnf install ./corerules-1.2.0-1.fc44.x86_64.rpm
Arch Linux, CachyOS, Omarchypacman corerules-1.2.0-1-x86_64.pkg.tar.zst sudo pacman -U ./corerules-1.2.0-1-x86_64.pkg.tar.zst
Bazzite, or any distribution with FlatpakFlatpak io.github.brahm.CoreRules.flatpakref flatpak install --user https://brahm.github.io/corerules/io.github.brahm.CoreRules.flatpakref
Any distribution (glibc 2.43+)AppImage CoreRules-1.2.0-x86_64.AppImage chmod +x CoreRules-1.2.0-x86_64.AppImage
Community Add-ons, for Linux, Windows and macOS.zip CoreRules-Community-Addons.zip In Core Rules, choose Import Add-ons… and pick the folder that holds the zip (how).
Windows 11Microsoft Store Core Rules on the Microsoft Store Free; the Store installs it with the Windows App Runtime it needs and brings every update.
macOS 14 or newer, Apple Silicon (M1 or newer).dmg CoreRules-1.2.0-arm64.dmg Open it and drag Core Rules to Applications, then let macOS open it once, as below.

Tested by players on Fedora 45 beta · Ubuntu 26.10 · Bazzite · Arch Linux · CachyOS · Windows 11 · macOS

Opening it on a Mac the first time

The Mac app is signed without a certificate from Apple and is not notarized, because the project has no Apple developer account. So the first time you open it, macOS refuses it and says it could not check it for malicious software. After copying it to Applications, run this once in Terminal, and from then on it opens like any other app:

xattr -dr com.apple.quarantine "/Applications/Core Rules.app"

Or, without Terminal, the Open Anyway steps:

Open Core Rules once, and press Done when macOS refuses it.
Open System Settings › Privacy & Security.
Under Security, press Open Anyway next to “Core Rules”, and confirm with your password.

Some Macs do not offer Open Anyway, and a Mac managed by a company or school may not allow the app at all. You need to do this again after each update. Macs have no CD drive, so File › Extract Data from CD… copies the rules data from the CD's ISO image or from a folder the CD's files were copied into.

The Flatpak comes from this site's own Flatpak repository, signed by the project, so flatpak update, GNOME Software and Discover bring every new version; it needs the GNOME 51 runtime from Flathub, which flatpak install offers to fetch. If you installed the CoreRules-1.0.0.flatpak file, which gets no updates, run flatpak uninstall --user io.github.brahm.CoreRules and install from the repository; your files stay. The AppImage bundles GTK, libadwaita and the other GNOME 51 libraries. Update Arch first (sudo pacman -Syu), or build the package from source with its PKGBUILD. The checksums of every file are in SHA256SUMS.

Release notes Source code

You need the original discs

This project contains no TSR or Wizards of the Coast content. The rules, books, monsters, pictures and help all come from a copy of AD&D Core Rules 2.0 (and, for everything the app creates and edits, the Expansion) that you already own. The app copies what it needs from the CD, its ISO image or an installation once, and then works without them.

If your discs are lost, scratched or unreadable, disc images have been preserved by the Internet Archive:

AD&D Core Rules 2.0 (1998)
AD&D Core Rules 2.0 Expansion (1999)

Copyright notice. AD&D Core Rules and its contents are copyrighted by Wizards of the Coast, and these images are not covered by this project's license. Download an image only if you own the original disc it replaces, and keep the data the app extracts for your own use; do not redistribute it. This project does not host these files and is not responsible for them. The links above are the archive's item pages, where you can read about each item before choosing whether to download it.

A lady ties a red sash on the arm of a knight in armour as he rides out — God Speed, Edmund Blair Leighton, 1900

A sorceress draws a magic circle on the ground with a wand — The Magic Circle, John William Waterhouse, 1886

The Community Add-ons icon, the Core Rules tome with a chest of scrolls

Twenty-five years of homebrew

Community Add-ons Collection

The add-ons that the Core Rules community made for Core Rules 2.0 and its Expansion, gathered into one package that the app imports in one go, on Linux, Windows 11 and macOS. 672 add-on packages became 36,525 items, in the Expansion's own format, so they open in the app and in the original program alike. The 668 pictures that came with them come along, and so do the texts their authors wrote.

7,479: wizard spells
3,514: priest spells
5,307: monsters
6,809: weapons, armor, equipment and magical items
1,547: races, classes and kits
584: encounters and templates
48: characters from the published modules
668: pictures of monsters, races and characters

One .zip · for Linux, Windows 11 and macOS

Download the add-ons (.zip) What's inside

Importing the add-ons

Download CoreRules-Community-Addons.zip and put it in a folder of its own. There is no need to extract it.
In Core Rules, choose Import Add-ons…: in the main menu on Linux, the More menu on Windows and the File menu on the Mac.
Pick the folder that holds the zip. The app reads it, with its subfolders and the zips in it, and lists what comes in, what was found twice and what cannot be imported, with why.
Press Import. The whole collection comes in in about a minute, with its pictures, and the module characters join the character list.

Needs Core Rules 1.2.0 or newer and your Expansion data in the app. Import backs up your UserDbas and Chars folders first and writes a log; importing again does not duplicate the characters. The same command imports any other folder of add-ons, loose or zipped. The original Expansion program imports the zip's Comunidade.xpx too. The link always gives the newest build; the addons release keeps each version. The collection leaves out Evermore's monthly goodies; the add-ons belong to their authors in the Core Rules community.

The Anti-Paladin, an add-on class — 584 classes after the import

The Achaierai, a monster type with its picture — Monster types with their pictures

Gerard Renier, a module character with his portrait — The module characters, with portraits

The accolade

Credits

The original application

The original application, AD&D Core Rules 2.0 (1998) and the AD&D Core Rules 2.0 Expansion (1999) for Windows, was published by TSR, Inc. and developed by Evermore Entertainment. All honor to the designers, programmers and artists who made them: this project exists because their work was good enough to miss for twenty-five years. Thanks also to the Core Rules community, whose add-ons are gathered in the collection, and to the Internet Archive for preserving the discs.

The modernization

Core Rules for Linux was made by Wagner Brahm and Claude (Anthropic), and is free software under the MIT License.

Copyright and trademarks

Advanced Dungeons & Dragons, AD&D, Dungeons & Dragons, D&D, D&D Beyond and TSR are trademarks of Wizards of the Coast LLC. AD&D Core Rules and its contents are copyrighted by Wizards of the Coast. All trademarks belong to their owners. This is an unofficial fan project, not affiliated with, endorsed or sponsored by Wizards of the Coast or Hasbro, and it contains none of their content.

The paintings

The paintings on this page are in the public domain, and were taken from Wikimedia Commons:

Knight at the Crossroads, Viktor Vasnetsov (1882). Public domain, via Wikimedia Commons.
The Bard, John Martin (circa 1817). Public domain, via Wikimedia Commons.
Saint George and the Dragon, Paolo Uccello (circa 1470). Public domain, via Wikimedia Commons.
The Magic Circle, John William Waterhouse (1886). Public domain, via Wikimedia Commons.
God Speed, Edmund Blair Leighton (1900). Public domain, via Wikimedia Commons.
The Accolade, Edmund Blair Leighton (1901). Public domain, via Wikimedia Commons.