I’ll try to explain using the example of Fury Charge.
Fury Charge is a positive effect that temporarily increases tower stats.1 Fury Charge gives:
- +2% attack speed
- +4% damage
Max Stacks 999
Duration 6 seconds.
Example: If we have a 10% critical hit chance and two "Common Critical Strike Fury" upgrades (50% chance to gain 1 Fury Charge on a crit), about 1 out of every 10 attacks will crit, and during that crit, there’s a 50% chance to gain 1 Fury Charge.
If we upgrade, for example, 10 "Common Critical Strike Fury" upgrades, that would be a 250% chance to gain 1 charge. This means that on a critical hit, we will gain 2 to 3 Fury Charges.