How to Use This Overlay

Open the DMG to a section. Open the DMGO to the corresponding section. The status marker at the top of the DMGO entry tells you immediately what to expect — whether the DMG rule applies as written, whether it has been changed, whether it has been replaced entirely, or whether it does not apply in Oath-Bound at all. The Legend explains each marker in full.

In most cases the marker is sufficient. An pass:[] entry means read the DMG section and run it. There is nothing further to do. The DMGO may add a brief note where context is useful, but if the rule stands as written, the overlay gets out of your way.

Where the rule has changed, the DMGO explains what changed and why — and where necessary, links to the Oath-Bound Rules Module (CRM) document that replaces or extends it.

The DMGO and the CRM are distinct documents with different purposes.

The DMGO is relational. It exists in reference to the DMG — its structure mirrors the DMG’s structure, and its entries are meaningful in that context. It tells you how Oath-Bound relates to the original. It does not stand alone.

The CRM is the live rules. It expresses what the Oath-Bound rules actually are, independent of the DMG. Where the DMGO records a deviation, the CRM contains the replacement. A GM who wants to understand a Oath-Bound rule in full follows the cross-reference from the DMGO into the CRM.

In practice, a GM running Oath-Bound will move between both. The DMGO is the first point of contact — it tells you quickly whether the DMG section is relevant and what has changed. The CRM is where the full treatment lives.

The DMGO does not reproduce DMG content. It references it. Section headings appear as navigation anchors; the content beneath them is Oath-Bound-specific commentary, not a restatement of what Gygax wrote. You need the DMG to use the DMGO — that is deliberate and will not change.

The DMGO also does not attempt to resolve every possible ruling. Where the DMG leaves something to GM judgment, the DMGO typically does the same — and says so explicitly. A {icon-dc-inline} marker means the rule stands but its application is at the table’s discretion. The overlay entry notes the decision point and any relevant considerations, but it does not pretend that a fixed ruling exists where one does not.

The DMGO is a living document. Sections that have not yet been reviewed carry the pass:[] marker. A pending section should be treated as applicable as written until a status is assigned. The pending marker is not an indication that something is wrong with that section — it means the review has not yet been completed.

The Preface gives the background and the reasoning behind the major departures from vanilla AD&D. It is worth reading before the overlay proper, particularly for a GM who is new to Oath-Bound.

The Legend explains the marker system. Read it before working through any section of the overlay — the markers appear on every page and their meaning should be clear before you encounter them in context.

After that, the DMGO does not need to be read linearly. It is a reference document. Work through it alongside the DMG at whatever pace suits preparation and play.