Set against the backdrop of the Horus Heresy, Legions Imperialis focuses on grand warfare, allowing players to recreate colossal battles and lead entire companies of their favorite Space Marine Legions. The game unfolds on an epic scale, aligning with Adeptus Titanicus and Aeronautica Imperialis, encouraging players to assemble a grand host that combines Legiones Astartes or Solar Auxilia with the formidable god-engines of the Mechanicum.
In Legions Imperialis, Detachments function as the equivalent of individual units in other Warhammer games, executing Orders assigned to them each round. Orders are initially concealed, challenging players to predict their opponent's plan and devise counter-strategies.
The gameplay features non-stop action, with Detachments alternating activation, ensuring continuous engagement on the battlefield. Players must adapt their plans on the fly, seizing opportunities as they arise in the midst of battle.
The battlefields of the 31st Millennium are perilous, with Titans annihilating entire tank squadrons, only to face destruction from strafing aircraft. Legions Imperialis games are visceral, with scores of warriors meeting their fate in a single round, emphasizing the importance of making every moment count.
In each Legions Imperialis game, the primary mission is to capture Objective markers, with Victory Points earned at the end of each round. This strategic element prevents a sole focus on eradicating foes, as opponents may secure victory through objective capture.
Strategic decisions commence before battle, with the army composition playing a crucial role. Infantry excels at capturing Objectives, while vehicles and super-heavies provide resilience and firepower. Each Detachment has a distinct role, requiring players to employ them judiciously.
Weapon selection is equally vital, with each Detachment armed to fulfill specific roles. Assault cannons excel against infantry but struggle against Titans, whereas Lascannons are ideal for targeting vehicles. Wise target selection is essential to maximize the effectiveness of arsenals.
Army building in Legions Imperialis centers around "Formations," essentially representing entire armies from Horus Heresy – The Age of Darkness. This flexibility allows players to construct forces tailored to their preferences, from a Legiones Astartes army mounted entirely in gunships for an aerial assault to a Solar Auxilia super-heavy tank company.
Utilizing battlefield terrain strategically is crucial—garrison buildings with infantry, conceal flanking elements behind ruined city sectors, or enhance tank squadrons' speed by navigating roads. Various terrain types with specific rules transport players to diverse environments, from crumbling hive cities to dense jungles, lava fields, and beyond. Notably, players can demolish buildings using the right weapons or a Titan's mighty fist.
