The random number syntax generates an integer value within the given range (inclusive of the minimum and maximum value). It can be used in scripts anywhere a numeric value is expected.
Waits for a random amount of time between 1 and 5 seconds.
if random(0, 100) <= 25 then give_item("ITEM_0001") else give_item("ITEM_0002") end
Gives either ITEM_0001 or ITEM_0002 to the player, with a 25% chance that the item will be ITEM_0001.