Curse

In-game: “Curse makes enemies tougher, faster and more numerous, and raises XP and gold.”^[1]

#The curse stat

Verified:

• Pest HP × (1 + curse) and pest speed × (1 + 0.3 × curse).^[2]
• Elite and boss HP × (1 + curse).
• The alive-enemy ceiling, the minimum crowd and the spawn rate × (1 + curse). The ordinary ceiling is capped at 500 on Easy/Normal, 650 on Hard and 800 on Nightmare; Hard/Nightmare also use a late ceiling floor.
• XP gain and gold gain × (1 + 0.5 × curse).^[3]

#Curses taken

Verified: separately from the stat, the game counts curses taken (+1 per Moldy Shrine accepted, +1 for Nightmare's starting curse). Every elite spawn adds floor(cursesTaken × 1) extra elites and every boss spawn adds floor(cursesTaken × 0.25) extra bosses. Each cursed extra drops 1 chest.^[4]

The first extra boss needs 4 curses taken: 4 Moldy Shrines on a level without a starting curse, or 3 on Nightmare because it starts with 1. Each extra boss is an extra chest.

#Sources of curse

• Rotten Spud: +0.1 curse per level (the curse stat only). It is also the catalyst for Landmine Harvest, Moon Cleaver and Kaboom Spud.
• Cursed Crown: +0.25 curse, +0.3 damage, +0.2 luck.
• Moldy Shrine: +0.1 curse, +1 curse taken and round((45 + 20 × minutes + 2 × minutes²) × gold gain) gold.^[5]
• Nightmare: starts with 1 curse taken, which works like accepting a Moldy Shrine: +0.1 curse and +1 curse taken (no gold).^[6]