The Battle Drone is a robotic ground-attack aircraft that appears in Earth Defense Force 5. It is similar to the UFO enemies from Monster Attack and Global Defence Force rather than the Gunship / Flying Drone enemy introduced in Earth Defense Force 2017.
Battle Drones are the mainstay of Primer aerial forces throughout the game, still forming the bulk of aerial attacks even when the more powerful Type 2 Drones start to make their presence known. They are fairly flimsy vehicles and not particularly powerful, but quite agile and compensate for their individual weakness with sheer numbers.
Their movements are less erratic than the Flying Drones of the previous game, tending more towards circling rather than bouncing around chaotically: they tend to stop moving briefly when lining up a shot. Their only weapon is a gun mounted on their underside that fires lines of energy bolts in a multi-shot burst.
They will tend to skim close to the ground while approaching, which can be a problem when using missile weapons as they will quite often cause the premature detonation of a volley, which can be disastrous with weapons like Emerald launchers and High-Altitude Impact Missiles which hang a large number of missiles in the air close to the user on firing.
On taking hits they will be knocked back, which will throw off the aim of any shots they are firing and force them to re-approach. This can be a problem with close-ranged weapons as gunfire can easily knock them out of the weapon's effective range. If they are pinned up against a wall by the knockback they will be unable to escape follow-on shots.
The game's greater focus on the aggro system for pseudo-stealth missions means the player is explicitly instructed on how it functions with Battle Drones: normally they are in an idle "search" mode with blue lighting on their gun and saucer, but when they move close to a player character or NPC or are attacked, they will light up red and enter combat mode. They will also alert any other Drones surrounding them: luckily this is only a one-step process, and the alerted Drones do not alert further Drones. Drones will also be alerted if other enemies are attacked in their vicinity, with the radius of effect seemingly defined by the type of enemy.
A more powerful type akin to a Mutant, this drone is much tougher than a regular Battle Drone and ditches the pulse weapon in favour of an extremely potent beam cannon that fires in a short burst.