I've been having an issue coming up with a good method to implement random item drops when monsters are destroyed in an RPG i'm working on. I need to come up with a way to do the following.
1. set the odds that an item will drop (10% chance each time)
2. Some items I want to drop and then never be able to drop again
3. some items have increasing/decreasing odds of dropping.
Any suggestions on good ways to implement this?