Hello I am a mastery 7 Gnar main and really love this champ. I played a lot of games with him and have 150 000 points on Gnar. This guide is still in progress and it's oriented by the progamers. I'm allways watching Gnar matchups from progamers and collect it all into this guide. I hope it helps you and i will allways update it after a new patch. And please notice that this guide is still in progress especially the Gnar jungle and AP Gnar guide which are just for fun °~°

In early game Gnar has to stay back and farm. You can poke your enemies down easily with your Q-Boomerangthrow or farm from long range with that ability. With your E you have high mobility and can escape jungle ganks by your doublejump. With your W you can get a lot of damage for trading and movement speed to escape or to chase your enemies down. You can also shred tanks with that ability because it deals damage equal of his maximum HP. After you gained enaugh rage by your passive by attacks or taking damage you turn into Mega-Gnar and get some HP back but it's not a healing so Spirit Visage wont increase the HP you get. In Mega-Gnar form you can try to trade with your enemy but you have to know that Mini-Gnar is fast, squishy and has high sustained damage and Mega-Gnar is slow tough and has high burst by his abilities. Gnar is a bruiser so your first items are AD items (Black Cleaver, Frozen Mallet) and then your last items are tanky items. Mid game is Gnar's strongest phase. there you can try to kill your enemy top lnaer, gank in mid lane or teleport into a teamfight. TP is a very important summonerspell because Gnar is a very big aspect in team fights. If you see that you are turning to Mega-Gnar and have your ultimate ready then you have to tp to bot lane or into a teamfight. with your ultimate you can stun all the enemies and then your team kill them. In late game just try to help your team in mid lane and try to win the game. And the most important thing for all top laners: Only a dead Teemo is a good Teemo! :)

Gnar in the jungle is very very difficult. You should start at the Golems. Pull is very important and maybe if you need to ask your team to tank a little bit of the damage. then you go to the red buff but dont fight him. Just kill one of the little ones. This is very easy just slow them down with your boomerang and then kill him so that the red buff wont hit you. After that go away from the red buff so that he wont attack you. When your smite's cooldown is on 10 seconds you can fight the red buff. Also smite him to get some health back. Then kill the birds and clear the other jungle with the blue buff. The rest is easy but take care that you wont get executed by the jungle monsters :P

AP Gnar is just a fun build. Your W (Hyper) has a 100% AP scalling so with a lot of AP you can deal a lot of damage with every third auto attack. I wouldn't say that it's bad but it is worse than the normal Gnar build. Basicly you start with items which give you attack speed and AP for example nashor's tooth. Then you just keep buying AP items and don't forget Hextech Gunblade because the healing you get with every third autoattack is so high that you can't die. also notice that AP Gnar is not tanky so you'd have problems in team fights. Normally you go top lane but if you want to you can also go to mid lane. Gnar has no mana so it wouldn't be intelligent to buy an item mana. Also max. your W first and take thunderlord's decree because the damage you deal with it is very high if you have a lot of AP.

Most common runes for beginners:

9 flat AD marks
9 flat armor seals
9 flat MR glyphs
3 attack speed quints

AD marks to win the traids and for easier last hits on minions. Armor seals to get less damage in early game. MR glyphs to get lessagic damage from your lane enemy or anyone else.

Runes for advanced players:

6 AD marks
3 AS marks
9 HP/lvl seals
2 AS quints
1 life steal quint

Glyphs:
9 flat MR again AP champion in the lane
9 scalling MR again many AP champions
6 flat CDR & 3 scalling CDR again AD champion in your lane and if there are not many AP champions in the rest of the enemy team

When you're better you dont need so many AD marks and AS helps you more than AD because of the W procs and fervor stacks. Scalling HP is for Gnar better than flat armor because in the team fights when you jump into al the enemies you will get physical and magic damage and HP protects you again both. Sure armor and MR ist better than HP but you already get that from your items and in the end you need both of them. With 1 life steal quint you get more sustain in lane which helps a lot but if you don't like you could also just stay at 3 AS quints.

As you all know Gnar has 0 sustain But there several options to get it. The first simple option is it to buy Vampiric Scepter. It gives you 10% lifesteal 15 AD and is cheap. But you dont buy it very often because sometimes it is a waste of gold, time and you dont need it. The next option is to buy Warmog's Armor. But the only problem at Warmog's Armor is that it has bad stats but still its a good option. THE BEST OPTION is it to increase your base health regeneration. Not for Mini-Gnar but for for Mega-Gnar. Mega-Gnar's base health regeneration is insane and if you buy items like Spirit Visage, Banshee's Veil or Zz'rot Portal (2 of them are enaugh) you have instant Warmog's effect in Mega-Gnar form with good stats and the healing wont decrease when you are fighting (you are in Mega-Gnar form for 15 seconds and you cant generate rage for 15 seconds when you turn back into Mini-Gnar)

Some people say that Mini-Gnar eould be stronger than Mega-Gnar but if Mini-Gnar would 1 v 1 Mega-Gnar then Mini-Gnar would win. You ask why? Mega-Gnar doesn't have much mobility so kiting is very easy on Mega-Gnar. Sure Mega-Gnar has a lot of damage and cc but not enaugh to one shot someone like a mage. In a normal game u need both of them. Mini-Gnar is fast, has a lot of damage and can shred tanks. Mega-Gnar is very tanky, has a huge amount of aoe damage and aoe cc. Mini-Gnar helps in the lane. He can poke his enemies down or kite/chase them and deal a lot of damage. Mega-Gnar has more damage damage and cc than Mini-Gnar but the problem is that it is very easy to kite him or run away. Mega-Gnar is great for team fights. Maybe he doesn't have a good escape/engage if he jumps in with his e but your team will help you so you won't die so fast. Randuin's omen andguardian angel are great item for Gnar because you can sloe the enemies down with Randuin's and if you die, guardian angel will revive you. Also items likd sterak's or Maw of Malmortius are great items because of the shield. You also habe a small engage when you turn bach into Mini-Gnar because you'll instantly get the hyper effect. Mini-Gnar in team fights is more a damage dealer. He should focus the tanks because he can shred them fown with his w but in the end both are important for the team. With Mini-Gnar you can survive and Mega-Gnar is great for the team because of the aoe damage and cc.

Normaly you start with a damaging item for example black cleaver but if you play defensive in early game (which is not a bad idea) then you start with a tanky item for example sunfire cape. Frozen mallet is a great starting item for Gnar because it gives you a bit defense, AD and the slowing effect is great in 1 v 1 or in chasing/kiting so build this as the first item most of the time. Start with black cleaver when you're doing good in lane or as the second item (after frozen mallet or a tanky item) when your lane opponent is also a tank. Again champions with big harras like Riven or Irelia you can start with with a sun fire cape and then buy frozen mallet. Or champions with crit like yasuo you can buy randuin's omen because of the crit. Again lane bullies like Teemo, Darius, Vayne or Quinn you should allways start with a tanky item.

AGAIN AP ENEMIES you should allways start with hexdrinker because it gives you AD, MR and a good shield. Then you decide: Are you going aggressive then buy Maw of Malmortius and after then Banshee's Veil. Or are you going defensive then buy Banshee's Veil first and then Maw of Malmortius. You could also start with Frozen Mallet again champions with true damage like Cho'Gath but thats your choise. As a third item Spirit Visage is great if the mid laner is also AP but sometimes two MR items are enaugh.

So in generall you start with an AD item if you go aggresive amd then only rush tanky items or you start with with one or two tanky items and then buy AD items if you play defensive in early game. OR THE THIRD OPTION is to go full tank if you play defensive all the time and if there is no more tank in your team. And of course don't forget boots as the second or third item depending on enemy team.