2 or more drops from enemies

[-Luke-]

How do i make let's say a 50% chance of sword and 40% chance of shield as drops. I know how to add one in treasure in the database but how do i make more items be droppable?

I am pretty new to RMXP and not good at finding stuff so make sure i can understand what you are saying, step-by-step or something would be nice.

~Thanks~Luke~