Expensive, extremely fast, and highly destructive, Black Bombs are commonly banned from games due to how difficult they are to stop.
Usage
Black Bombs, alongside Fighters, are the fastest units in the game, being able to move nine spaces a turn and are not hindered by terrain. Black Bombs do not attack other units in a traditional fashion, and instead have an "Explode" command. When directed to Explode, the Black Bomb will detonate on the spot, dealing 5 HP damage to all units within three spaces of the black bomb, regardless of unit type or allegiance. This will instantly destroy the Black Bomb in the process, but will never destroy other units (any units with 5 or less HP will be reduced to 1 HP). Since the Black Bomb can move and Explode in the same turn, they can do extreme damage to enemy unit formations while giving them no ability to counterattack. Defensive lines can easily be weakened immediately by a Black Bomb, allowing other units to follow and mop up whatever remains.
The only shortcoming of the Black Bomb is its high fuel usage and low fuel capacity. It consumes 5 fuel at the start of each day, and if told to move its maximum distance for even a few days will quickly deplete its fuel stock. If a black bomb runs out of fuel, it will crash and be destroyed on the start of the turn of whomever owns it, dealing no damage whatsoever. To use Black Bombs further away from Airports, an APC is recommended to keep its fuel stock high.
Damage dealt from a Black Bomb is not considered to be combat damage, so it is not subject to Luck, will not damage Pipe Seams and will not charge the CO Power Bar of any armies damaged by it.
Fighting Against
Black Bombs are extremely difficult to fight against, their high movement combined with their high range and damage means they can easily find an optimal spot to Explode and do its damage. While any unit capable of attacking Plane-Type units can OHKO a Black Bomb at 8 HP or above, the high movement of the Black Bomb makes it difficult to attack without leaving your own units vulnerable in the process. It is not worth it to attack a Black Bomb unless you can completely destroy it, as unlike other units, having lower HP does not reduce the Black Bomb's combat effectiveness.
The best way to combat a Black Bomb is to try to block it from reaching your more valuable units with cheaper, more expendable units, such as Infantry. To be considered cost effective, the Black Bomb must do around 25000 funds worth of damage to the opponent, and detonating a Black Bomb against Infantry is money wasted. However, note that Black Bombs can also be indirectly cost effective through the damage they facilitate, such as by softening defensive walls, allowing other units to break through and deal a decisive, game-determining blow to more valuable units that would have otherwise been protected. Due to their fuel usage, Black Bombs tend to have a limited effective range away from Airports and APCs, so denying it the use of refueling opportunities can lower its effective range temporarily.