Gwen Runes explained
There's one set of runes for Gwen on patch 15.12 that is the clear favorite for LoL players and pros alike. The best Gwen rune paths on the position 
Top are 
Precision as the primary path and 
Resolve as the secondary path with a pick rate of 48%. Besides picking runes on Gwen you should learn how to play Gwen and if you are interested in pro matches take a look on how a pro builds Gwen. If you want to discuss 
Gwen then you should visit the champion subreddit.
Gwen runes from primary path
Precision improves attack and sustained damage on Gwen troughout the match. Most of high elo players – and our LoL pros in the the major regions – have agreed that 
Conqueror is the best keystone rune to run on Gwen. This keystone rune provides additional power in the later stages of a game. As soon as Conqueror is fully charged, Gwen deals additional damage and gains life steal. Other primary runes on Gwen are 
Presence of Mind, 
Legend: Alacrity and 
Last Stand.
Presence of Mind helps Gwen with the mana problems by restoring missing mana, if a champion is killed. Legend: Alacrity grants additional attack speed to Gwen. With Last Stand you deal more damage while you are at low health.
Gwen runes from secondary path
When it comes to your secondary path, most Gwen players prefer to go with Resolve. Resolve empowers the survivability of Gwen and increases the tankiness. On the Resolve path, the best runes for Gwen are 
Bone Plating and 
Unflinching.
Bone Plating make Gwen overall tankier, by decreasing the amount of poke damage in the early game. Unflinching inceases Gwen tenacity based on your missing health.
FAQ for Gwen Runes
Which is the best keystone rune on Gwen?
The best keystone rune on Gwen is Conqueror. This Gwen runes setup is then referred as Gwen Conqueror.
What runes does Gwen use?
Runes from the paths Precision and Resolve are the most used runes on Gwen. For the exact pick rates of Gwen runes used, you have to study the rune distribution presented.