The book is explicitly tied to the terrain set (released alongside it):

Overall, the community agrees this is a fantastic supplement that elevates the Ironhead Squat Prospectors into one of the most characterful and well-supported gangs in all of Necromunda.

A standout feature of the (2024/2025) supplement is its transition of the Ironhead Squat Prospectors from a "gimmicky" secondary gang into a fully fleshed-out faction with "House of..." level support . Key features that enhance gameplay and lore include:

A dedicated D66 table featuring 18 unique Gang Tactics for the Halls of the Ancients. Key Gang Components

As a narrative-driven expansion, Halls of the Ancients is praised for its outstanding background information, which significantly enriches the history of Necromunda.

Players will find a complete, updated Ironhead Squat Prospectors gang list. Key additions include:

The 2021 supplement focuses on a specific event: The discovery of a massive, sealed data-temple belonging to a forgotten human civilization. The gangs of Necromunda—Orlock, Goliath, Escher, Delaque, Van Saar, and Cawdor—are not fighting to destroy it. They are fighting to download its data before the other Houses or the Imperial authorities (the Palanite Enforcers) shut it down.

The random loot table in Halls of the Ancients is notoriously broken (in a fun way). You can find:

This is a critical point for clarity. The search term "Necromunda Halls of the Ancientspdf 2021" points to a source of confusion.