If you want an event, where the thieves steal all your gold, what do you specify?
I guess for negative events to properly function, they should be a lot more configurable, perhaps by allowing the modder to specify multiple outcomes:
What happens if no items present (below minimum range of required items): No message (event skipped), or failure message (take nothing)
What happens if some of the items are present: no message (event skipped), failure message (take nothing), partial success message (take whatever you can)
What happens if all of the items are present: success message (take all)
And who said that negative events have to only remove items? They could both take items and give items at the same time. Or crafts?
Hmm. This is pretty complicated, because conditions are normally only checked in eventScripts, which are only executed at the beginning of the month, but here we'd need to check conditions when an event happens during a month. So basically, when event happens, it would have to instantly trigger an eventScript, which would check the item conditions and conditionally trigger negative events depending on item presence and item count...