The Tyranids are an all-consuming alien swarm from beyond the known galaxy. Driven by the vast and ineffable intellect of the Hive Mind, their tendrils drive into fresh systems with every passing hour. These single-minded metapredators cannot be reasoned with, bought off, or put to flight. They seek only to strip each new world they encounter, devouring every shred of biomass to feed the relentless advance of the hive fleets and leaving dead, airless husks in their wake. Endlessly adaptable, the Tyranids possess no mechanical technology. Instead, their weapons and wargear are symbiotic or parasitic organisms, bonded with their wielders and capable of annihilating prey with hails of bio-acid, living projectiles, and ravaging psionic energies. From seething masses of warrior organisms to malevolent leader-beasts and walking battle-tank-sized monsters, the Tyranid swarms are as nightmarish as they are unstoppable. The Warhammer 40k Codex Tyranids 2023 book is an essential guide for anyone who wants to collect Tyranids and unleash the power of the Hive Mind on the tabletop. Inside these pages, you’ll find all the rules you need to play a Tyranids army in games of Warhammer 40,000 – including Crusade and Combat Patrol rules – along with detailed accounts of their rapacious behaviour, divergent hive fleets, horrifying biotechnology, and invasions past and present.