Vibro weapon
Vibro weapon are a class of weapons with special adaptive penetration (PV) mechanics.
While most weapons have a specific penetration value that does not change, such as 6, vibro weapons adapt to the armor of the enemy, and a vibro weapon's penetration value is always equal to the opponent's armor value (AV). For example, if you attack a 
snapjaw brute with AV 
1, the vibro weapon's effective PV is 1. On the other hand, if you attack a 
leering stalker with AV 25 with the same weapon, the weapon's effective PV is 25. As a result, vibro weapons can be extremely effective against powerful late-game enemies, especially for characters who have low strength.
A vibro weapon's adaptive PV is represented with a wavy equals sign in game: ( ≈ )
Penetration Chances
The following table indicates the chances of penetrating one or more times with a vibro weapon when a target is hit (for more about hit chances, refer to the Hit Roll topic).
The +1, +2, and +3 columns indicate the chances when a PV bonus is in effect, such as when you mod the vibro weapon with Sharp or Overloaded, or if you're using Long Sword aggressive stance. For example, you can obtain a +3 PV bonus by combining a Sharp-modded vibro weapon with Improved Aggressive Stance.
| Vibro Weapon | Vibro Weapon +1 | Vibro Weapon +2 | Vibro Weapon +3 | |
|---|---|---|---|---|
| At Least 1 Penetration | 99.2% | 99.9% | 100% | 100% |
| At Least 2 Penetrations | 47.9% | 70.9% | 99.2% | 99.9% |
| At Least 3 Penetrations | 8.7% | 21.9% | 47.9% | 70.9% |
| At Least 4 Penetrations | 0.3% | 2.1% | 8.7% | 21.9% |
| At Least 5 Penetrations | 0.0001% | 0.02% | 0.3% | 2.1% |
| Average # Of Penetrations | 1.561 | 1.948 | 2.561 | 2.948 |
Equippable Vibro Weapons
Natural Vibro Weapons
- \bite (ickslug)
- \rust-pitted saw
shoulder-mounted light cannon- \stony bite (molting basilisk)
Special Cases
The 
geomagnetic disc is a special case in the vibro category. Even though it shows the vibro symbol in its penetration indicator in-game, it does not work the same as other vibro weapons. Instead of matching the target's AV, it ignores AV entirely and deals its damage directly to the target(s). For more info, refer to the Vibro sub-section of the geomagnetic disc page.