List building in Legions Imperialis gets an update with Liber Strategia, a 240-page book that collects and updates previous content from core rulebooks, The Great Slaughter, The Devastation of Tallarn, and The Rise of the Dark Mechanicum. 

 It contains complete up-to-date Detachments and Formations for Legiones Astartes, Solar Auxilia, Mechanicum Taghmata, Dark Mechanicum, Collegia Titanica, and Knight Households – the latter of which replace the Strategic Asset rules from the Legions Imperialis rulebook – making it an indispensable resource for all Legions Imperialis players. Detachments for the new Legiones Astartes units seen below can also be found in this book.