Introduction

This website is the Advanced Dungeons & Dragons 1st Edition Player’s Handbook Overlay (PHBO) — a section-by-section record of the relationship between the Advanced Dungeons & Dragons 1st Edition Player’s Handbook (PHB) (Gary Gygax, TSR, Inc., 1978, ISBN 0-935693-01-6) and the Oath-Bound rules system as it applies to players and their characters.

The PHBO does not reproduce the PHB. It mirrors its structure and records the decisions — what was kept, what was changed, what was discarded, and what was replaced with something built specifically for Oath-Bound.

You need a copy of the PHB to use the PHBO. It is not a standalone rulebook. That said, the differences that matter most for character creation and play are explained here in full. A player who reads the PHBO carefully can build and run an Oath-Bound character without memorising the PHB in advance.

The PHB’s internal organization is more regular than it might appear on first reading, but its section hierarchy is not always obvious — headings do not consistently signal their own importance, and topics sometimes appear in unexpected places. It is a product of its time, designed before conventions for rules documents had settled into anything like a standard.

The PHBO follows the PHB’s structure, section by section, rather than reorganising it into something cleaner. Rationalising the structure would introduce a second organizational scheme to reconcile against the first, and would not obviously help either a new reader or one who already knows the book.

Where page references are provided in the PHBO, they are there as a navigation aid — a way of anchoring the overlay to the original document when the original’s own signposting falls short.

Oath-Bound uses percentile dice (d100) as its primary resolution mechanism. As a player, what this means in practice is that your character’s capabilities are expressed as percentages rather than bonuses, and that fine distinctions between characters — minor advantages, small differences in training or equipment — are more precisely expressed than a d20 allows.

The conversion is not total. d100 was adopted where granularity adds value. Where a d20 provides adequate resolution, it was left alone. The arithmetic is not complex. Most players adjust within a session or two.

Parts of this website and substantial parts of the broader Oath-Bound corpus were produced with the assistance of AI tools — principally Claude (Anthropic) and ChatGPT (OpenAI). That is worth being honest about, both because the contribution was real and because the nature of it is probably not what you might assume.

The design decisions are not AI’s. The world, the rules, the opinions embedded in the PHBO — those came from decades of play and the particular convictions that accumulate over that kind of time. AI did not design Oath-Bound. What it did was something more useful than I expected.

The first thing it gave me was discipline. Game design, like most creative work, tends toward productive tangents — interesting questions that lead somewhere worthwhile but not where you were going. Left to my own devices, those diversions accumulate. Having an agent that tracked the thread of an argument, pushed back when a decision was underspecified, and kept the session aimed at a defined outcome turned out to matter more than I anticipated. It is not that the diversions were wrong. It is that they needed to be logged and returned to, rather than allowed to swallow the original task.

The second thing was organization. The raw output of a design session — the decisions, the rationale, the edge cases — is not a document. Turning it into one requires a kind of editorial work that is slow and unrewarding to do alone. AI was consistently useful at taking a body of confirmed decisions and producing structured, navigable prose from them. The thinking and much of the language is mine. The shape of it on the page often is not.

Beyond the rules work, AI was also used extensively in world design — and here the role was different again. Building a coherent world requires a kind of relentless internal consistency checking that is easy to defer and hard to do alone. Having an interlocutor that would push back on implausible claims turned out to be one of the more valuable parts of the process. The world gets more internally consistent when someone is paying attention to the gaps. AI was willing to pay that attention at two in the morning when no one else was.

Every page on this website carries a :content-origin: attribute in its header — Human, Claude, ChatGPT, or Mixed — that records where the content came from. That record is immutable. It does not change as pages are polished or revised. Readers who want to know the provenance of a specific page can find it there.

The Advanced Dungeons & Dragons 1st Edition Player’s Handbook — the PHB — was written by Gary Gygax and published by TSR, Inc. in 1978. All rules content in that document is the property of its respective rights holders. Nothing in the PHBO reproduces that content. Section headings are used as structural references only, in the same way that a commentary cites the work it discusses.

Original hardback copies of the PHB have become collector’s items. First printings command significant premiums and clean copies at any printing are increasingly hard to find at a reasonable price. For practical working use, Wizards of the Coast has made both the PHB and its companion the Dungeon Master’s Guide (DMG) available as PDFs and print-on-demand editions through DMs Guild:

The print-on-demand editions reproduce the 2012 premium reprints rather than the original printings. The content is identical for the purposes of the PHBO. Page numbers and chapter bookmarks are consistent with the originals — references cited throughout this website can be trusted against either edition.

Which brings us to an utterly shameless plug.

If you can work from reprints or electronic formats, getting started as a player costs very little. This website has free access. The PHB is available as a modestly priced print-on-demand edition. In a system where rules awareness is expected to emerge through play, and character generation is a process undertaken with the group, even the PHB is not mandatory. A player who wants to read ahead can. One who would rather just sit down and play is not disadvantaged.

The heavier lift belongs to the GM, not the table.