Orders were altered to bounce automatically to adjacent units within 6 inches of the original target. This "splash" mechanic allowed a single officer to command an entire frontline, reducing the need to buy excessive numbers of HQ models just to pass out basic buffs. Turret Weapon Rule
This article provides an in-depth look at what made this particular codex a monumental release for players, examining its rules, lore, and impact on the tabletop. What is the 9th Edition Astra Militarum Codex? 9th Edition Astra Militarum Codex Pdf
Officers became more flexible, able to issue orders to both infantry and armored vehicles. This allowed commanders to make tanks more accurate or infantry more disciplined, simulating the rigid command structure of the Astra Militarum. 3. Dedicated Regiment Rules Orders were altered to bounce automatically to adjacent
Optimized for aggressive special weapon output. What is the 9th Edition Astra Militarum Codex
Since a legitimate PDF from GW doesn't exist, your next best bet is the physical copy. By the time you are reading this, the 9th edition codex has been officially rotated out of production. GW has stopped printing it in favor of the 10th edition index and eventual 10th edition codex.
Even though Warhammer 40k is currently in its 10th Edition, demand for the 9th Edition Astra Militarum Codex remains steady for several reasons: