Olaf/Strategy

Skill usage

 * Because of effect and,  is one of the fastest junglers in the league.  allows him to gank effectively, and the combination of  and  let him both sustain his health throughout the early game and effectively take on and defeat most other junglers.
 * is a versatile ability and offers many different utilities to :
 * It is a very useful ability for chasing because of its own cooldown reduction (if you can pick it up while chasing). Throwing your axe where you are likely to chase your opponent lets you refresh its cooldown much quicker and increases its slow uptime.
 * It is an effective harassment ability. While many skillshots are consumed upon hitting the first target, will travel straight through all enemies it hits. At early levels, however, recklessly spamming it will quickly deplete your mana.
 * will benefit from the damage buff of, so you can use it to enhance your harassment slightly. This is even more mana-intensive for Olaf, however.
 * It will remove the fog of war in a large area around where it is thrown for a very brief duration, making it useful for checking bushes.
 * Although sustained damage output isn't very powerful during early game, his burst is surprisingly strong as his  deals a significant amount of true damage which cannot be mitigated by any means. With a few ranks invested in the ability it can devastate the health of most squishier champions during mid game.
 * If you have not invested in significant HP as you level it, it can also fairly quickly devastate the health of himself if you are not careful with its usage. By this token, it can often be unwise to spam this during a 1v1, as he can potentially wind up helping to kill himself.
 * can combine, , and at low life to become deceptively tanky. This makes him a great duelist, as he can take on most champions even at low health. When combined with items and spells such as  and , he can become formidably hard to kill.
 * After purchasing a few health items, can deal significant damage while  is active.
 * can be used either as an initiating ability, as a defense ability in battle or as an escape ability because of the immunity to crowd control effects.
 * strongest role during the lategame is to function as a bulky assassin. One of his most effective strategies during lategame teamfights is to activate, single out the opposing carry or AP mage and quickly slay them before the opposing team can kill him. Because of the complete CC immunity grants him, he becomes extremely difficult for the opposing team to peel from the carry.
 * Try to cast with as low health as possible, granting you as much attack speed from  as you can which allows for more autoattacks that grant life steal from  while you are immune to being stopped by crowd-control effects... but obviously, don't cast it too late.
 * When playing, try to drag games into late if you don't feel you have an advantage. Once he has his full build, he becomes nearly impossible to stop.

Build usage

 * naturally receives armor and magic resistance from the active effect of, and also gains additional bonus damage from based on his maximum health. Because of this, stacking health on him is a very common build path.
 * Consider or  if you're looking for a build with one sole health item. A  is one of the most useful items for, as in addition to the large amount of health it has, it slows any opponents he autoattacks, letting him chase very effectively. However, if the player is confident with their ability to consistently land  on a fleeing opponent, then  can be substituted for a  for its much greater health and survivability boosts.
 * ,, and  are all possible alternative health and aura options for , and each offers different benefits.  is a powerful defensive option for him against any physical damage-heavy team, and  can make excellent use of the active to assist him in killing the opposing carries during teamfights.  grants himself health and cooldown reduction for his  and  as well as lifesteal and attack speed to nearby allies.  can bolster his effectiveness against teams stacking heavy armor and general survivability against physical damage.  is simply a cheap item for  as well as his entire team to get fairly tanky early game. Because it will postpone buying other items  so desperately needs, it should be only be bought if no one else will and if strongly needed.
 * is always a decent choice when building a lot of health. The bonus attack damage based on health will stack with . Even though it doesn't excel in any particular regard (offensively or defensively), it is pretty cheap.
 * Some form of lifesteal or health regeneration is advised when dealing damage with to negate the health cost.
 * is a good highly offensive item for with the lifesteal stacking with .  paired with  is a large amount of health regeneration while also rendering pretty much any magic damage caster useless against  and offering much appreciated movement speed.
 * is a great item for in lane. He can use all of the item's traits very well, and its lifesteal allow him to focus on leveling his other abilities over  yet not be lacking for sustain.
 * A synergizes incomparably well with 's kit - the passive attack damage boost as his health drops increases his DPS exponentially when combined with, and the magic damage shield lets him stay at low health more safely.
 * may be a better magic resistance choice when has a strong desire or need to be a bit more tanky.
 * Cooldown reduction synergizes well with as well as . With maximum cooldown reduction (40%),  can be activated every 3 seconds and the cooldown on  is 0.3 seconds after picking up the axe as the flat cooldown reduction from picking up the axe becomes even more effective. For the sole purpose of maintaining the slow of, as long as Olaf picks up the axe within 2.5 seconds of throwing it, 12.5% cooldown reduction is all that is needed for the target to be permanently slowed.
 * has no dash ability, so purchasing or using  or  can help him escape or initiate battles easier.
 * is an option as well, as it gives 40% movement speed for 3 seconds. The additional health, health regeneration and mana regeneration will also largely solve any sustainability problems. If bought early, the gold per 10 from can make a noticeable difference as the game progresses.
 * can greatly augment carry-killing power by cutting their attack speed by 20%, in addition to its very useful armor and cooldown reduction bonuses.
 * , and  all offer very heavy armor penetration for, and work in different situations. , in addition the above mentioned benefits, currently grants the highest flat armor penetration of any item, meaning that in tandem with armor penetration runes, masteries and ,  can effectively do true damage to lightly armored champions. By contrast,  and  are superior against heavily armored targets, offering percentage penetration and reduction, respectively, which synergizes well with the flat penetration granted by.

Jungling

 * Starting items:,  x5
 * Skill progression: →  →  →
 * Jungling order: Wolves → Blue Golem (Smite) → Wraiths → Wolves → Small Golems → Wraiths → Fountain → Red Lizard (Smite) → Gank
 * Smite goes well with the spell vamp of.
 * Throw just in front of you to deal damage and immediately pick it up. This is an extremely fast way to jungle after the Olaf changes in V1.0.0.135 while providing a very good initiator when ganking.  does damage to yourself which can make ganking difficult when leaving the jungle with lower health.

Countering

 * Before engaging, keep in mind that he becomes very strong when he is at low health due to his . Properly judge if you can burst him down with your abilities, or he may just lifesteal it back and kill you.
 * is a slow projectile, meaning that you can dodge the spell easily.
 * You can deny from spamming  by preventing him from picking up the axe that the spell left in the path.
 * In a similar vein, making significant course changes while is chasing you will prevent him from picking up his axe and continuing to close the distance on you.
 * Save your CC while is using . It removes and negates any CC cast on him while it is active.
 * also gives him bonus armor and magic resistance. It might be wiser to wait until the buff duration is over before committing to attack him.
 * As is immune to any forms of CC placed upon him, the most effective forms of keeping him away are self-displacement abilities such as  and player-created terrain such as . You should try to save these abilities for when he uses his ultimate to make him waste the duration.

Champion spotlight
http://www.youtube.com/watch?v=YuC3ZUY88d8