In the center of the room, on a pedestal of black stone, lay the Liber Imperium. The tome was bound in a strange, scaly material that seemed to shift and writhe in the flickering torchlight. As Elian reached out to touch the cover, the room was filled with a blinding flash of light.

Rules for adding lethal assassins from various clades (Vindicare, Culexus, etc.) to loyalist armies. How to Use the Content Effectively

The Liber Imperium is a gift to the Warhammer 40,000 community—a chance to play the sprawling, bureaucratic, terrifying might of the Imperium of Man in all its flawed, combined-arms glory. But a gift that is corrupted, outdated, or illegible is no gift at all.

If you are a tabletop wargamer, "better" typically means having the most up-to-date errata. Games Workshop frequently releases magenta-inked updates to correct unit profiles and weapon behaviors.