Zeri Runes explained
There's one set of runes for Zeri on patch 15.11 that is the clear favorite for LoL players and pros alike. The best Zeri rune paths on the position 
Adc are 
Precision as the primary path and 
Inspiration as the secondary path with a pick rate of 56%. Besides picking runes on Zeri you should learn how to play Zeri and if you are interested in pro matches take a look on how a pro builds Zeri. If you want to discuss 
Zeri then you should visit the champion subreddit.
Zeri runes from primary path
Precision improves attack and sustained damage on Zeri troughout the match. Most of high elo players – and our LoL pros in the the major regions – have agreed that 
Lethal Tempo is the best keystone rune to run on Zeri. This keystone rune gives Zeri a great head start in team fights and allows to put out more damage in that time window. Other primary runes on Zeri are 
Triumph, 
Legend: Alacrity and 
Cut Down.
Triumph restores on Zeri a part of missing health and award bonus gold, if a champion is killed. Legend: Alacrity grants additional attack speed to Zeri. If the enemy team consists of multiple tanks, then the rune Cut Down is the best choice.
Zeri runes from secondary path
When it comes to your secondary path, most Zeri players prefer to go with Inspiration. Inspiration opens creative opportunities on Zeri troughout the match. On the Inspiration path, the best runes for Zeri 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 Zeri Runes
Which is the best keystone rune on Zeri?
The best keystone rune on Zeri is Lethal Tempo. This Zeri runes setup is then referred as Zeri Lethal Tempo.
What runes does Zeri use?
Runes from the paths Precision and Inspiration are the most used runes on Zeri. For the exact pick rates of Zeri runes used, you have to study the rune distribution presented.