What are rolls?
Whenever you open a crate, it creates a roll and runs it - a roll is essentially an animation, for example CS:GO crates or the Encircle roll.
List of Rolls
Rerolls are a chance to get another reward - you can toggle this in crate config. The GUI is also completely customizable to your liking.
You can make rerolls require a permission (
ecocrates.reroll.<crate>) - it is given to all players by default, so negate the permission if you don't want a rank to be able to reroll.
You have to enable rerolls in your crate config for rerolls to work at all.