Phosphorus Coating

 is an item found in Red Dead Redemption Undead Nightmare DLC pack.

Characteristics
Phosphorus Coating is an item that can be selected from the kit section of Marston's satchel. It requires one type of any sage (e.g. Red Sage, Desert Sage, Hummingbird Sage) and one Violet Snowdrop to use. When used, it coats all of Marston's bullets and shells in phosphorus causing any Undead hit to be lit on fire, leaving them to slowly die in distinct blue flames. However, the treatment only lasts for a limited amount of time before another use is required.

Obtaining
Phosphorus Coating is an item given to you by Nigel West Dickens after giving him 5 Desert Sage and 5 Violet Snowdrop during the first task of his mission A Cure for Most of What Ails You.

Tips & Tricks

 * It is best used to kill large, tight clusters of Undead as to hit as many targets as possible before the phosphorus treatment wears off, or when the player is low on Dead-Eye as bodyshots with the treatment will still inevitably kill the Undead, albeit slower than a headshot.
 * When facing several Bolters, Phosphorus Coating can simply light them up compared to the more tedious method of using Dead-Eye to target their heads.
 * Using phosphorus treated ammo to light the Undead on fire counts towards Undead Sharpshooter Rank 3, meaning that you can quickly light 5 Undead and then headshot them all in quick succession.

Trivia

 * When a phosphorus coated round is fired, it leaves behind a green trail similar to that of a modern-day tracer round.
 * Phosphorus coated rounds are similar to the modern-day equivalent of the incendiary round.
 * The blue flames that engulf enemies from phosphorus treated ammo are similar to the flames caused by Holy Water.
 * Phosphorus coated rounds function like that of their normal counterparts when fired at humans.