Description

A series of three expansion books for Warhammer 40,000 third edition. Like the Book of the Astronomican for Rogue Trader, this short-lived annual collected articles from White Dwarf featuring various new rules, updates to the game, and army lists - some official, others merely experimental. There is substantial overlap between the volumes as each subsequent one was in part meant to update and/or collect much of the material of the previous.

The original in the series, Chapter Approved, was published in 2001, with Chapter Approved 2003 following in 2002 and Chapter Approved 2004 in 2003 (the year in the title indicating the coming year rather than when it was published). They were also known as the Second, Third, and Fourth Book of the Astronomican, respectively, in homage to the original from Rogue Trader.

Army Lists
- The Cursed Founding for use with Codex: Space Marines
- Feral Orks for use with the Codex: Orks
- Imperial Guard Armoured Company
- Kroot Mercenaries
- Tyranid Seeding Swarms
- Tau Rail Rifle for use with Codex: Tau
- Mounted Daemonettes for use with Codex: Chaos Space Marines (3rd Edition, 2nd Codex)

Miscellaneous Rules
- Transport Vehicles
- Vehicle Design Rules
- Tyranid Monstrosities

Scenarios
- Pitched Battle Mission
- Escalating Engagement Mission

Codex Updates
- Codex: Space Marines
- Codex: Armageddon
- Codex: Orks
- Codex: Blood Angels & Codex: Catachans
- Codex: Eldar & Codex: Craftworld Eldar
- Codex: Necrons
- Codex: Dark Angels
- Codex: Dark Eldar

Trial Rules
- Trial Assault rules
- Trial Vehicle rules
- Minor Psyker Powers