Weapon durability is sort of a big deal in the Souls games (including Bloodborne). As you use your weapon, it loses its edge, and the damage it deals starts to go down. To restore it to its optimum state, you have to repair it periodically, so that you aren’t being unnecessarily held back in a world which is already pretty hostile and difficult to maneuver.
Dark Souls II features this same mechanic, but in all versions which feature 60FPS gameplay – that’s the original release of the game on PC, as well as Scholars of the First Sin on PC, PS4, and Xbox One – weapons degrade twice as fast as they should, because durability seems to be tied to some sort of cumulative framerate count since last weapon repairs. It’s absolutely annoying, and can interrupt the flow of your gameplay needlessly.
Thankfully, a fix to this bug has been released by From Software, which makes weapon damage degrade at the normal rate- currently, it is just available on PC (for both, Scholars of the First Sin, as well as the original Dark Souls II release), but the console patch can’t be too far behind.
So now when you die because your weapon had grown blunt, it will be entirely your fault!