Serration is a hidden form of damage in Bloodborne.
Serration is a hidden damage modifier, inherent in weapons, which deals 20% more damage against "Beast-type enemies".
This damage is applied before bonuses such as the open foe bonus for a multiplicative effect. However, there are two category of beings that, though classified as "Beasts", are considered so in the sense of them being animals, rather than "True" Beasts (check the page Beasts to understand the distinctions).
As there are many bosses who are indeed "True" Beasts, it would be wise to upgrade one of these weapons along with your preferred weapon.
Weapons that deal Serrated damage
(Serrated attacks always have a 20% bonus damage against beasts)
- Beast Cutter (both modes)
- Church Pick (both modes)
- Saw Cleaver (short mode only)
- Saw Spear (both modes)
- Threaded Cane (whip mode only)
- Whirligig Saw (buzzsaw mode only)
Enemies weak to Serrated damage
Bosses weak to Serrated damage
- Abhorrent Beast
- Beast-possessed Soul
- Blood-starved Beast
- Bloodletting Beast
- Cleric Beast
- Darkbeast Paarl
- Father Gascoigne (third phase only)
- Laurence, the First Vicar
- Loran Darkbeast
- Loran Silverbeast
- Ludwig, the Accursed (first phase only)
- Vicar Amelia
- Watchdog of the Old Lords
- Serrated damage only affects "True" Beasts.
- It can be wise for players to infuse weapons that have Serration with Fire as it will multiply the damage further when attacking Beasts. Though any build will benefit from this, Arcane builds can utilize it to its fullest potential.
- If a player becomes part Beast by the use of Beast's Embrace, the Serration bonus does not apply to them.
- Serration is used, in-lore, to cause bloodletting on Beasts. Indeed the weapons that cause Serration damage sport jagged and sharp edges.
- The reason that the Serration bonus does not apply to players who use Beast's Embrace is likely because becoming a Beast is not just a physical state, but rather a state of mind. In other words, since the players are still conscious of their action, they cannot be Beasts, and therefore the effect does not apply.