Drop rates

[BloodReaver]

Hey how can I make a unit have like a 10% chance to drop something?

 

[Kenoriga]

If you have the unit preset, you can double click on that units and go under "Items Dropped".

Else, you need to trigger it.

Events
   A unit dies
Conditions
   Unit-type of Triggering Unit is equal to <this>
Actions
   If (Random integer from 1 to 10) is equal to 1
   Then Item - Create <item> at Position of Trigger Unit

And clear leaks.