auto(500)

local rune = "heavy magic missile rune"

local target = getattacking()

if target.id ~= 0 then
    local item = finditem(rune)
    if item.id ~= 0 then
        if target.ismonster and target.hppc > 0 and gethp() > 1500 then
            item:useoncreature(target.id, target.stackpos)
        end
    end
end