Object: allItems
{
items: [item1, item2, item3, item4]
size: 4
}

Item: item1
Item: item2
Item: item3
Item: item4

Player: {
i:
items [item1,item3]

Event: "Give Random Item" {
// Rolls a new number while player has the respective item
// Gives player either item2 or item4 when the whole loop has complete

i = -1
while(i < 0 || hasItem(allItems.items[i]))
i = floor(rand(0,allItems.size))

giveItem(allItems.items[i])
}
}