Vex Runes explained
There's one set of runes for Vex on patch 15.14 that is the clear favorite for LoL players and pros alike. The best Vex rune paths on the position 
Mid are 
Domination as the primary path and 
Inspiration as the secondary path with a pick rate of 46%. Besides picking runes on Vex you should learn how to play Vex and if you are interested in pro matches take a look on how a pro builds Vex. If you want to discuss 
Vex then you should visit the champion subreddit.
Vex runes from primary path
Domination improves burst damage and assassination tools on Vex. Most of high elo players – and our LoL pros in the the major regions – have agreed that 
Electrocute is the best keystone rune to run on Vex. This keystone rune provides burst damage, aiding them in nuking down the enemy carries. Other primary runes on Vex are 
Cheap Shot, 
Grisly Mementos and 
Ultimate Hunter.
Cheap Shot makes you deal more damage to enemies with impaired movement, which has great synergy with the setup of Vex. Ultimate Hunter scales up Vex ultimate haste on every unique champion takedown.
Vex runes from secondary path
When it comes to your secondary path, most Vex players prefer to go with Inspiration. Inspiration opens creative opportunities on Vex troughout the match. On the Inspiration path, the best runes for Vex are 
Cosmic Insight and 
Biscuit Delivery.
Cosmic Insight grants summoner spell and item haste. Biscuit Delivery is a great rune for laning as it gives additional health and mana, which can help in more aggressive lanes.
FAQ for Vex Runes
Which is the best keystone rune on Vex?
The best keystone rune on Vex is Electrocute. This Vex runes setup is then referred as Vex Electrocute.
What runes does Vex use?
Runes from the paths Domination and Inspiration are the most used runes on Vex. For the exact pick rates of Vex runes used, you have to study the rune distribution presented.