Base Raid game mode allows you to attack (raid) other players' bases in hopes of defeating them and stealing their resources.
In Base Raid, you either attack another player's base, or defend your own base from other raiders. To defend your base, you must build defensive machines like the Plasma Cannon, Lightning Tower, etc. Those machines will help you fend off raiders and possibly stop their attacks before they take down your base. To attack a base, you must build offensive machines that will allow you to train troops. These troops will be used during a base raid alongside your Main Squad.
To train Troops, you will need to first build both the Barracks and Cadet Dorm machines. After that, head to the Troops training modal in the bottom left of your screen:
What are troops?
Troops are deployable assets that you can train (create) using their respective machines. There are different troops types with different roles. For example, a Mercenary is an all-around troop that has balanced HP and DPS, a Super Swole is a tank with low DPS but High HP.
How do you train troops?
Each troop type has it's own corresponding machine. For example, to train Super Swoles, you must build the Super Swole Squad Department, to train Mercenaries, you must build the Mercenary Wolvez Hideout. Each troop type has it's own Housing Space Requirement, and to increase your Housing Space, you must build and upgrade the Cadet Dorms. The higher your MF level, the higher you can upgrade your Cadet Dorms. Troops training costs Space Elixir.
How do you upgrade troops? Building and upgrading the barracks unlocks additional levels to the Troop machines, for example: if your barracks is level 2, then your Mercenary Wolvez Hideout can be upgraded to level 2. The higher the barracks level is, the higher you can upgrade your troop machines and unlock higher level troops. Upgrading offensive machines costs Space Elixir.
Raiding a player has a cooldown of 8 hours. That cooldown can be increased by acquiring certain Holder Exclusive Machines.