User blog comment:TheTobarMethod/So...Tri-Force Vayne lol?/@comment-90.48.83.249-20130303083534

triforce on vayne is bad for various reasons ( unless you drop the PD for it lategame as last item)

1: too expensive   to have AS quick in the game and vayne needs it

2: procs... you don't need   it to chase under ult, you're vayne

3: health ... uy a wamrmog or a GA as ddef item it's much better

your build lacks any def item :  the assassins will just jump on you and you'll go BOOM (remember vayne's AA range, you can't really be safe even if well positioned, kha's jump has twice her AA range, zed can swap + ult from far.. vi can ult   from far etc...)

and trust me if you play an adc with no defensive items against people who know the game a bit and get ulted by vi or zed, you're dead , it's not about positioning , it's about  lack of range to deal damage vi can always Q + flash + ult and then the mid or top jumps with her and you die before the CC is finished ( you can't cleanse vi's ult)