VoxelCore compiles single-parent inheritance before content is published.

Within the same namespace, a local parent key can be used. Cross-pack references are valid only when the parent namespace is declared as a pack dependency.

| Value | Behaviour |

|---|---|

| omitted scalar | inherit parent value |

| provided scalar | replace parent value |

| explicit `false` | replaces inherited `true` |

| list | explicitly supplied child list replaces parent list |

| `properties` map | recursive deep merge |

| render metadata | field-by-field merge |

| structured `custom_model_data` | semantic-key merge when parent and child are both structured |

| switch numeric ↔ structured CMD | child representation replaces parent representation |

Only one parent is supported per item.

Compilation rejects:

- missing parents;

- self-cycles or longer inheritance cycles;

- duplicate ContentIDs;

- definitions that remain invalid after resolution, such as missing required material;

- illegal cross-pack references without declared dependencies.

The resolver includes dependency-chain context in compilation errors so invalid authoring fails at load/reload time rather than surfacing as a gameplay error later.

A definition can remain `bound: false` and serve only as an inheritance base. It still participates in compilation and the runtime registry, but current `/voxelcore admin item list` filtering hides it from the user-facing list.