You can apply Poison and Rot simultaneously in Elden Ring. You can stack them to deal extra damage to your enemies.
However, you will only see one visual effect when applying Poison and Rot simultaneously.
Scarlet Rot often overwrites the visual effect of Poison but you should see two damage ticks close together. They indicate you’ve successfully stacked Poison and Rot.
Rest assured, both are active at the same time.
Poison may not be as powerful as Scarlet Rot but will steadily chip away at your enemies’ health bar.
After a while, Scarlet Rot will run out and you’ll see the green effect of Poison too.
Scarlet Rot works a lot like Poison. It drains HP fast leaving your enemies vulnerable to attacks. Poison drains HP slowly but surely.
⇒ Quick Tip
Players noticed that wearing the Mushroom Crown and Kindred of Rots Exultation helps you deal massive damage when hitting your enemies with Poison and Rot.
Some bosses are resistant or immune to Rot
Keep in mind that some enemies and bosses are resistant or even immune to Scarlet Rot and Poison.
For example, Malenia is resistant to Scarlet Rot. Godfrey, the First Elden Lord is also pretty resistant to Scarlet Rot.
Royal Knight Loretta is immune to Scarlet Rot. Nothing happens if you use Scarlet Rot against this boss.
Keep this detail in mind and enjoy playing Elden Ring!