Maokai Runes explained
There's one set of runes for Maokai on patch
12.10
that is the clear favorite for LoL players and pros alike. The best Maokai Runes on the position 
Support are Inspiration as the primary path and
Resolve as the secondary path with a pick rate of 47%. Besides runes you should take a look on Maokai Build and if you are interested in pro matches take a look at Maokai Probuilds. If you want to discuss
Maokai then you should visit the champion subreddit.
Primary runes path on Maokai
Inspiration opens creative opportunities on Maokai troughout the match. Most of high elo players – and our LoL pros in the the major regions – have agreed that
Glacial Augment is the best keystone rune to run on
Maokai. This keystone rune slows enemy champion on your first basic attack. This slow can by followed up by a skill shot of Maokai to force the opponent in a dangerous situation. Other primary runes on Maokai are
Hextech Flashtraption,
Minion Dematerializer and
Cosmic Insight.
Having an extra way to decrease the distance with the
Hextech Flashtraption will make an engage much easier to pull off.
Minion Dematerializer will help you to control the position of the minion wave.
Cosmic Insight grants summoner spell and item haste.
Secondary runes path on Maokai
When it comes to your secondary path, most
Maokai players prefer to go with
Resolve.
Resolve empowers the survivability of Maokai and increases the tankiness. On the
Resolve path, the best runes for Maokai are
Bone Plating and
Unflinching.
Bone Plating make Maokai overall tankier, by decreasing the amount of poke damage in the early game.
Unflinching inceases Maokai tenacity based on your missing health.
FAQ for Maokai Runes
Which is the best keystone rune on Maokai?
The best keystone rune on Maokai is
Glacial Augment. This Maokai runes setup is then referred as Maokai Glacial Augment.