Looks like you've done well developing a system for modifiers. But the data the system is driving could also use some attention.
The modifier that resulted in this issue was Lifesteal, shown in my tooltip as 1% Lifesteal
Here's my research on the subject
Best unit of measure
This modifier affects player health so that's the unit of measure, health points (hp).
Range of Value
This defines the size of the theater in which Lifesteal acts.
Health points are integer values that range from a minimum of 1hp to a maximum of 20hp on a starting character.
Visual indicator in the Heads Up Display (HUD) changes by half a heart/hp,
Related Info
It takes a player approximately 3-5 hits to down a typical 20hp mob.
Recommended adjustment to Lifesteal balance
Use 1hp as the smallest possible change in health points, with increments measured in health points.
In the screenshot, the sword does 6hp of damage, so 1hp is 1/6th of that.
1/damage = 1/6 = 0.1678 = 17% of the weapon's damage is 1hp.
So for example, if I wanted the 6hp of damage from this sword to heal for 2hp:
1/6 × 2 = 0.3333 = 33% of sword's damage is 2hp worth of healing.
Looks like you've done well developing a system for modifiers. But the data the system is driving could also use some attention.
The modifier that resulted in this issue was Lifesteal, shown in my tooltip as 1% Lifesteal
Here's my research on the subject
Best unit of measure
This modifier affects player health so that's the unit of measure, health points (hp).
Range of Value This defines the size of the theater in which Lifesteal acts.
Health points are integer values that range from a minimum of 1hp to a maximum of 20hp on a starting character. Visual indicator in the Heads Up Display (HUD) changes by half a heart/hp,
Related Info It takes a player approximately 3-5 hits to down a typical 20hp mob.
Recommended adjustment to Lifesteal balance
Use 1hp as the smallest possible change in health points, with increments measured in health points.
In the screenshot, the sword does 6hp of damage, so 1hp is 1/6th of that. 1/damage = 1/6 = 0.1678 = 17% of the weapon's damage is 1hp.
So for example, if I wanted the 6hp of damage from this sword to heal for 2hp: 1/6 × 2 = 0.3333 = 33% of sword's damage is 2hp worth of healing.