The drone cannon Ex-B is a unique weapon added to Fallout 3 by the Mothership Zeta add-on and carried by experimental weapons drones.
Characteristics
The Ex-B (Explosive-bolt) is apparently an alien experiment in equipping the guardian drone model with a cannon that fires energy balls that explode on impact, instead of bouncing around. The Ex-B has a very long range if you manually angle the shot correctly. For example, you can be well outside Evergreen Mills and still hit the trapped super mutant behemoth. The Ex-B can also work underwater.
The drone cannon is an ineffective V.A.T.S. weapon, as the fired projectile will arc towards its target; since the game doesn't compensate for gravity in V.A.T.S., this can leave the projectile several meters away from its intended target.
Durability
The drone cannon Ex-B can successfully fire about 417 times from full condition before breaking, the same amount as a normal drone cannon.
Variants
Comparison
| Legend | ||||
|---|---|---|---|---|
 | - Weapon name (melee or unarmed) |  | - Attacks in V.A.T.S. | |
 | - Weapon name (gun, energy or explosive) |  | - Action point cost | |
 | - Damage per attack (damage per projectile) |  | - Damage per action point | |
 | - Damage per second |  | - Weapon spread | |
 | - Area of effect damage |  | - Magazine capacity (shots per reload) | |
 | - Effect damage & duration |  | - Durability (number of attacks before breaking) | |
 | - Bonus effects |  | - Weight | |
 | - Attacks per second |  | - Value in caps | |
 | - Critical chance % multiplier |  | - Value to weight ratio | |
 | - Critical damage |  | - Skill required | |
 | - Critical effect damage & duration |  | - Strength required | |
 | - With all mods attached | |||
| | | | | | | | | | | | | | | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Drone cannon  | 40 | 466.7 | 100 | Timed detonation | 3.33 | x1 | 50 | 30 | 4.7 | 0.5 | 1 | 417 | 18 | 1999 | 111.1 |
| Drone cannon Ex-B | 40 | 466.7 | 100 | Impact detonation | 3.33 | x1 | 50 | 30 | 4.7 | 0.5 | 1 | 417 | 18 | 1999 | 111.1 |
Location
In the Weapons Lab, there is a room where you can spawn brahmin for the drones to kill. Enter the room and kill the drone for the weapon. There is also a second one in the same room that is automatically activated when the first is destroyed.
Bugs
When shot, the projectile will occasionally pass through walls or the floor and do nothing.- In some accounts, when shot the projectile will just disappear as soon as it hits the target, damaging it but not exploding.
- When shot into deep water, the projectile will disappear, and then reappear and seemingly "float" in place on the surface without exploding. Projectiles fired onto the floating projectile will attach and stack, also without exploding.
- In V.A.T.S. mode, the Ex-B seems to aim like a normal drone cannon, landing short of the enemy as if expecting the projectile to bounce.
- The Pip Boy recognizes the Ex-B as an unobtainable (obtainable only through console commands) weapon, evident in its picture (which is also missing).
Gallery
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||