The Arm of Orion has overrun New Madrid, one of the most remote colonies of the Empire. The United States Imperial Forces have sent an army into orbit to take control. Part of this army is the 8th Armored Infantry, also known as Section 8, composed of the best soldiers the UISF has to offer. They are equipped with full-body armor that allows them to jump from a spaceship and land on the planet without any parachute or other help. The single-player campaign puts the player in the shoes of Alex Corde and his squadmates to help free New Madrid. Section 8 is a multiplayer-focused first-person-shooter where killing enemies, capturing control points, and completing dynamic combat missions grant victory points. Up to 40 players can participate in each battle, with dynamic combat missions coming in six types such as escorting a Commando or deploying an outpost. The player has access to various weapons, equipment like repair tools, and passive modules that increase their shield capacity or weapon damage. Players can change their loadout not only when they're dead but also on the field at deployable supply depots. Supply depots are either created automatically by the game once certain objectives have been met or can be bought and built by players who have earned enough money by killing enemies and completing objectives. Combat structures such as turrets, a tank, and armored transport are available for purchase.
The armor of Section 8 has features like an integrated jetpack for short periods of flight and a booster to temporarily run faster. These functions consume energy, which is automatically replenished when not used. The Orbital Burn-In method allows players to control their spawn point to some extent. While a soft landing allows for immediate combat, it makes the player vulnerable during drop-down, while a hard landing results in a fast recovery but leaves the player momentarily stunned.
Conquest is the only gameplay mode available, with different bot modes such as Balanced, Coop/Extreme Coop, and Swarm/Super Swarm. The One Man Army-mode is available only in single-player, pitting the player against an entire team of hostile bots.