Powerup Drop Chance
Powerup Drop Chance is a stat that increases your chance of getting chests or powerups when killing an enemy. The game uses two formulas: one for the chance of a chest dropping when killing an enemy and one for normal powerup drops, both of which use a time factor that ramps up over time and resets when you get a drop.
Essentially if you upgrade your Powerup Drop Chance to 2.0x (from 1.0x) you are twice as likely to have chests & powerups drop when killing enemies (amongst the ones that do not give you a guaranteed drop).
Chest drop chance (per kill):
Normal powerup drop chance (per kill):
- PowerupChance: The stat explained in this article. Its starting value is 1.0× (e.g. if you upgrade it to 10× that means you'd use 10 in the formula).
- chestDropBase: Base rate for chest drops. Fixed at 0.0005 and never changes.
- eliteMultiplier: 1 for normal enemies, 2 for elite enemies.
- enemyBasePowerupDropChance: Seems to be fixed at 0.01 for all enemies.
- timeFactor: A value from 0 to 1 that increases over time and resets to 0 when a drop occurs.
- For chest drop chance, it reaches 1.0 after 420 seconds without any chests dropping from a regular/elite enemy
- For powerup drop chance, it reaches 1.0 after 120 seconds without a powerup drop.
- The time factor resets to 0 when a normal or elite enemy drops a chest (Note: It does not reset if something like a boss or challenge shrine drops a guaranteed chests.). After that it'd take another 420 seconds to reach 1.0 in the timeFactor variable for chests. 120s for powerups.
Essentially if you upgrade your Powerup Drop Chance to 2.0x (from 1.0x) you are twice as likely to have chests & powerups drop when killing enemies (amongst the ones that do not give you a guaranteed drop).
Formulas for chests & powerup drop chance
Chest drop chance (per kill):
$$\text{chestDropChance} = \text{chestDropBase} \times \text{PowerupChance} \times (\text{timeFactor} \times 2) \times \text{eliteMultiplier}$$
Normal powerup drop chance (per kill):
$$\text{powerupDropChance} = (\text{timeFactor} \times 2) \times \text{PowerupChance} \times \text{enemyBasePowerupDropChance}$$
Variables
- PowerupChance: The stat explained in this article. Its starting value is 1.0× (e.g. if you upgrade it to 10× that means you'd use 10 in the formula).
- chestDropBase: Base rate for chest drops. Fixed at 0.0005 and never changes.
- eliteMultiplier: 1 for normal enemies, 2 for elite enemies.
- enemyBasePowerupDropChance: Seems to be fixed at 0.01 for all enemies.
- timeFactor: A value from 0 to 1 that increases over time and resets to 0 when a drop occurs.
- For chest drop chance, it reaches 1.0 after 420 seconds without any chests dropping from a regular/elite enemy
- For powerup drop chance, it reaches 1.0 after 120 seconds without a powerup drop.
- The time factor resets to 0 when a normal or elite enemy drops a chest (Note: It does not reset if something like a boss or challenge shrine drops a guaranteed chests.). After that it'd take another 420 seconds to reach 1.0 in the timeFactor variable for chests. 120s for powerups.
Example values (when time factor = 1.0)
At 1.0× Powerup Chance:At 2.0× Powerup Chance:
If the time factor was at 0.5 all the chances would be halved.