Antewise

Synthesis — Defect Attack Card in Slay the Spire 2

Updated 17 Oct 2026 Source Slay the Spire 2 card data (spire-codex.com API), 577 cards retrieved 17 October 2026 By
Data status: The facts on this page were checked against the source named above. Game values can still shift with a patch, so re-check anything that looks off.
Synthesis card art
Synthesis

Deal 14 damage. The next Power you play costs 0 1 Energy.

CharacterDefect
TypeAttack
RarityUncommon
Cost2 Energy
TargetAnyEnemy
Total damage14
Per Energy7.00 → 10.00 upgraded

Card text

Deal 14 damage. The next Power you play costs 0 1 Energy.

Upgraded: Deal 20 damage. The next Power you play costs 0 1 Energy.

Where it sits on the curve

Measured the same way as our efficiency tier list: total damage divided by Energy.

Synthesis produces 7.00 per Energy at base and <strong>10.00</strong> upgraded. That ranks it 83 of 143 of the 143 attacks with a fixed cost. It sits in the top 43% on this measure.

The measure ignores everything that is not a number. Area damage, conditions and drawbacks are not priced in.

Other Defect cards at 2 Energy

  • Adaptive Strike — Deal 18 damage. Add a 01 Energy copy of this card into your Discard Pile.
  • All for One — Deal 10 damage. Put ALL 01 Energy cards from your Discard Pile into your Hand.
  • Buffer — Prevent the next time you would lose HP.
  • Bulk Up — Lose 1 Orb Slot. Gain 2 Strength. Gain 2 Dexterity.
  • Consuming Shadow — Channel 2 Dark. At the end of your turn, Evoke your leftmost Orb.
  • Feral — The first time you play a 01 Energy Attack each turn, return it to your Hand.

Where to go next

All 577 cards — the full table, filterable by character. Efficiency tier list — every measurable card ranked.

Rarity system explains how often this card appears. Enchantments covers the modifiers that can change it.

Frequently asked questions

What does Synthesis do in Slay the Spire 2?

Deal 14 damage. The next Power you play costs 0 1 Energy.

What does upgrading Synthesis change?

Deal 20 damage. The next Power you play costs 0 1 Energy.

How much does Synthesis cost?

2 Energy. It is a Uncommon Attack card.

Is Synthesis efficient for its cost?

It produces 7.00 damage per Energy, which ranks 83 of 143 among the attacks that can be measured this way.

More Slay the Spire 2 guides

Sources

Figures and item data on this site are read from the game’s own reference wiki before publishing. Where a value could not be confirmed there, the page says so instead of filling the gap.