Directly in 1978 . <| sep |> The crit damage is always going to be worth more . Cait will start to scale nicely with zerker boots , runaans and IE . Going RFC before IE is going to delay your main damage spike your IE significantly . Especially as headshots aren ' t going to contribute as much to your damage as critting for 250 % 50 % of the time will . Also note that building RFC after IE is going to feel a lot better than building RFC before IE because each point of crit and attack speed from RFC is going to be worth more than it would otherwise be due to the crit multiplier and AD from IE . If you were to go Hurricane RFC you would be feeling rather shitty because you ' d be prolonging your mid game slump IMO . If you go Hurricane IE RFC or whatever else you ' re going to feel a lot better about yourself and be doing much , MUCH more damage in fights , especially in shorter skirmishes where you can ' t reliably get multiple headshots off . disclaimer I don ' t really play ADC , this is just based off of maths in my head