Spire Growth is a trinket in Fiend Folio, a mod for The Binding of Isaac.

Each card use grants a temporary damage up that scales with the internal id of the card used.

The following formula is used to calculate the damage bonus: 0.2 × CardId ^ (5 × 0.1752) × SpireGrowthCopies.

The damage boost is drained by 0.06 per second.

Some cards have a set boost they can give which is independent of their id, meaning their CardId in the above formula is different:
• 2 of Clubs/Diamonds/Spades/Hearts: 3
• Ace of Clubs/Diamonds/Spades/Hearts: 2
• Suicide King: 13
• Queen of Hearts: 12

Some modded cards also have a specific boost set, however since this is set by internal id rather than card name, having other mods enabled can apply the boost to a different modded card.

Spire Growth can be found in the following item pools:

The following special synergies and interactions for Spire Growth have been documented.

* Note that not all possible synergies and interactions are listed here.

• Check out the trinket description on the mod's external Wiki.
• Download Fiend Folio from the Steam Workshop.