This Olaf build focuses on Tanky and good damage dealer, I like to play tanky Olaf and later in the game, you will be almost immortal and will damage very well. Olaf is my favorite champion, he was my first Champion for 3150 Ip

TECHNO VIKING!

Olaf was my first champion for 3150 Ip, For me he's is the best Champion I ever played. Well How I play Olaf, I start with Boots of Speed and 3 Health Potions or Dorans Shield (Your Choice) I go to my lane and start farming, Why I set in Vicious Strike alot? Well that is because I play tanky Vicious Strike is scaled on Health, And with Frozen mallet and Warmogs it gives you alot of damage (Spell Vamp - Lifesteal Too) And the best combo is when you buy Atmas Impaler, Best Combo ever, More health more damage, Well When I am level6 I recall and get Ruby Crystal, If you got more gold you can buy Phage, Now I got it I go back to my lane keep farming and pushing and at level 9 I go for ganks. Why? Cause then you got your vicious strike in Rank 5, 21% Life steal and Spellvamp and your team mate in mid lane should be around level 11-13, Something you should do Is get the Red Buff, Everytime it respawn go and kill it, Cause slow for Olaf is amasing, There we have why I set in Undertow next Cause It gives you slow and good harras in your lane, Reckless Swing is good to but not good enough, It takes down your health and not I need when you play tank Olaf, Blue buff can always be good but when someone else need it like a Mage or Amumu give it to them.

I love to jungle with Olaf but I don't play it so much only in need, You start with a Cloth armor and 5 Health potions and then go to wolves when you have killed them go to Golems after that go to Wraith and kill them after kill Ancien Golem and then Lizard Elder, Do this rotation when jungling and when you have reach level 6 you can go for ganks, Cause you need Olaf's ultimate alot in ganks, No slows and it gives your Armor Penetration, After ganks just keep jungling till you get like Level 13 then you can go to lanes and gank all the time, Well what you should buy is Wriggle's Lantern, Then take Berserker Greaves or Mercury's Treads, If you want fast ganking take Boots of Swiftness, Well the 4 next items will be Frozen Mallet, Warmog's armor, Atmas Impaler, Infinity Edge.

Tanky Damage
Great chaser with Undertow if you can land it.
Nice Jungler
Can soak up a lot of damage and extremely hard to kill late-game.
Techno Viking!

Hard to chase a range
Hard to solo lane with
Expensive Build
Big mana problems withour Blue Buff
Prone to early game harassment and easily kited.

Why I choose these items? Well Mercury's Tread gives you Tenacity and Boosts up your magic resistence against ranged mage, Cause olaf have hard laneing agaisnt ranged mage, Frozen Mallet Is a MUST cause of the Health and slow and Of Couse the +20 Damage, Warmog's Armor is a Must to if you playing tanky Olaf because of your Vicious Strike, Warmog's armor gives you 1370 Health and 45 Health Regeneration, then we have Atmas Impaler my favorite item with Olaf because that item gives a great Combo with your Vicous strike, Both skill/item are scaled on health, and yea Atmas give you armor and critical chance that Is great, Why I take infinity edge? Yea that is because it gives you alot of damage and Nice critical strikes very good for Olaf's damage, and Phantom Dancer isn't a most I often take it because of Vicious Strike, Well I not start or rune with attack speed because pf that you got he's Awesome Passive, You got change out Phantom Dancer till Trinity Force or Force of Nature.

This was my build for Olaf, Maybe not the best one but this is how I play how Olaf and He's a very fun champion, Recommended champion and very rewarding once you get the hang of his Q, Feel free to ask any questions

TECHNO VIKING FOR THE WIN!