How does Poison work in Slay the Spire 2?

In Slay the Spire 2 (STS2), Poison is a damage-over-time debuff that makes an enemy lose HP at the start of its turn, then decreases by 1 each turn. It remains one of the most important scaling tools for Poison-based decks.

Poison timing and decay

Poison damage is dealt at the start of the afflicted creature's turn.
After dealing damage, the Poison amount decreases by 1.
If an enemy has 10 Poison, it will take 10 damage at the start of its next turn, then the stack will drop to 9, and so on.

Why Poison is strong in STS2

Poison rewards decks that can repeatedly apply or increase stacks over several turns. It is especially powerful when:

You can stall fights safely with Block and control tools.
You combine Poison with cards that double or transfer stacks.
You fight multi-phase or high-HP bosses where long-term damage matters more than single hits.

Where to learn more about Poison in STS2

To go deeper on Poison decks and synergies, you can explore:

The status effects & keywords page for a full definition of Poison and related combat terms.
The cards database filtered to Silent Poison cards and supporting tools.
Future build guides focused on Silent Poison decks and multi-enemy fights.