Hi there folks, I'm here to introduce you to what I have found the as the best way to play Warwick, the Blood Hunter, I do this because Warwick has been my main for the past 7 months and I see way too many people doing mistakes with Warwick and making stupid builds such as Tankwick or Magewick.
One of Warwick's problems is that he doesn't have a «set» build, which made him unpopular, because when you play an AD carry you know you must get an Infinity Edge, a Phantom Dancer and a Bloodthirster, this, however, does NOT happen with Warwick, he benefits from so many stats it's hard to make a definite build, my goal with this build is to get all those stats together and create Warwick's evolution: RIPWICK!

Warwick's theme is that of a hunter, think of the enemy champions as your prey, basically you play the role of the predator that puts said prey down.
Warwick has two abilities that support this, first being his E Blood Scent, whenever a wounded Enemy is nearby, you detect their presence and gain a movement speed bonus, thus giving you the tools required to chase and hunt said champion. Warwick's ultimate, Infinite Duress also supports this, when you use it, you lunge at an opponent and tear them apart while preventing them from fighting back, this coupled with Blood Scent allows you to chase your foes and then kill them with your ultimate.
Warwick also has a lot more team utility than most people think, this will be explained later in the guide.

As stated before, Warwick is a hunter, Tanks aren't hunters, they are protectors, wardens, and in this game a tank's role is to initiate and disrupt the enemy team, some say Warwick has «TONS» of disruption and can initiate well with Infinite Duress, this, however is false, because if you jump at someone in the middle of 4 people, chances are you will get stunned, and then, due to your low damage output because you built tank and your zero capability to disrupt your foes, you will be ignored, your team will be mauled and then so will you.
Regarding Magewick , Warwick, does have a 100% AP ratio spell, which is his hungering strike, however, this already deals a lot of damage based on your foe's Health, so you need a LOT of ability power to make this ability significanty stronger, the cooldown is also relatively high for the damage it will deal with AP nevertheless, and as such, Magewicks have no value whatsoever in fights, which is what wins games.

Pros:
Very strong 1v1, especially with attack speed
Insane Sustain
Great late-game
Easy to use

Cons:
Is harassed with ease due to being melee
No flash or dash besides ultimate
Ultimate must be used carefully in teamfights
Ultimate is easily disrupted by silences, knockups, knockbacks or stuns.

Build 1 is a lot safer than build 2,however, build 2 is a lot stronger, you will be easier to kill but you will deal more damage and as such you are more susceptible to being focused in fights.

Note: build 2 is also considerably expensive when compared to build 1, always bear this in mind when using build 2.

These masteries focus on damage, improving both your summoner spells and taking both armor and magic resist penetration to increase damage and healing (both very important on Warwick)and topping it off with Executioner, because it synergises immensely with Warwick's death combo(which I will show you in a bit).

The defensive masteries focus on health because Warwick doesn't gain a lot of health per level, these masteries are quite strong both early and later in the game.

Ah runes, how I hate and love thee....Runes are an important aspect of playing your champion.

Marks,the offensive runes,Warwick now deals a weird mix of magical and physical damage, though that doesn't make him a hybrid, because he scales poorly with AP unlike other possible Hybrids like Teemo or Kayle, thus he needs magic penetration but 0 Ability power and still needs Armor Penetration, as such, the only viable marks are the Greater Marks of Destruction, which give both.

Seals are known for being the defensive runes, as stated earlier, Warwick's health pool isn't very big, sogreater seal of vitalityGreater Seals of Vitality are the most obvious choice, however, you can use these armor seals instead.

Glyphs, the utility or magic resist runes, in this case Greater Glyphs of Shielding are the best Magic Resistance runes possible, so we take them because we do not want utility since Warwick is neither a support nor a tank.

Quintessences, you have some freedom of choice here, since these are strongest and most versatile runes, you can pick from movement speed ones or hybrid penetration ones, like your Marks.

This is a must because it emphasizes Warwick's Hunter theme.

This is a must because of the synergy it has with your ultimate.

If you wanna jungle, replace it with exhaust, however, you shouldn't be jungling with this build, but of course feel free to adapt it and use it to fit Jungling.

I find no other summoner spells to be acceptable on Warwick, and don't mention Flash, Flash is for people who commit mistakes and then want a free ticket out of the trouble they themselves created, if you play Warwick, there isn't room for mistakes.

This is your bread and butter ability, it's a higher than melee range nuke that heals you for a big chunk of the damage it deals, which is based on your foe's maximum health or incase their maximum health is very low, it deals flat damage based on rank.(% of max health damage based on rank too.) Whenever you can, use it on enemy champions who get close to you in the lane.

This may at first seem a meh ability, but coupled with the item build above, when you use this ability, your attacks go faster than the speed of light...why? Because you reach the attack speed cap, meaning you regen more health than anything else in the game.

This ability is ranked last because it obviously doesn't help in fights, be aware however that it defines Warwick as what he is, a Hunter, after fights, injured enemies will most likely attempt to flee, this ability ensures you don't let them do so, at level 18, when you detect someone with this, you will reach a massive 570 Movement Speed, your foes will neither be able to run NOR hide!

This is your ultimate ability, basically you jump at an enemy champion and start eating them alive, dealing damage and preventing any reaction whatsoever(some exceptions exist), DO NOT USE THIS TO initiate teamfights! It will be wasted because you won't get a kill, it will be stopped by stuns/silences and it will transform you into DEADWICK, this ability is meant to be used on low HP champions to kill them and render them useless before their death, when using it, make sure you use your Hungering Strike on the target, after the channel completes, Hungering Strike will go off and ignore flashes, normally netting you the kill, MAKE SURE YOU HAVE ENOUGH MANA FOR THIS!
Ignite is also a must because coupled with this skill you can drop someone from half health to Zero without allowing any counterattack.

Enemies in your lane near or below half their HP? You want a kill? No problem! The Ripwick combo will on most circumstances net you one, assuming all conditions are met:

Step One: is your enemy below or at half Health? If yes, go to step three, if not, go to step two.

Step Two: If you have a lane partner, try asking him to harass said enemy, if you do not have a lane partner, harass your foe yourself without putting yourself at risk, use for this, then go back to Step One.

Step Three: Is your mana enough for your Ultimate and one Hungering strike? If yes, go to step four, if not, go to step five.

Step Four: Cast your ultimate and ignite on the target, followed by a Hungering Strike WHILE channeling your ultimate, bam! You have ripped an enemy!

Step Five: No mana? Sounds like you spammed your Q on minions or maybe you wanna play Magewick eh? Lol, just kidding, wait until you have enough mana and go to step four.

Apparently Mobafire is bugged, the stats it shows above are not the stats you have at level 18, you have a lot more attack speed and damage, health and movement speed.

This is the only Doran's items that makes sense in a normal game, you need a boost in damage and you're a bit squishy(though you do have sustain), I've seen people use Doran's Ring and seriously IT IS NONSENSE! You are not supposed to use your Q to farm or whatever, it's supposed to be used in FIGHTS or to harass, not to be spammed on minions like I have seen so many Warwicks doing.

This item is INSANE on Warwick, it will make your ultimate deal 20% of the target's max health as magic damage (basically it's an EXTRA hungering strike that doesn't heal you) it makes soloing Dragon and Baron a breeze because you deal damage based on their max health and they have A LOT of it, and the armor and AD are definitely very strong too, overall this item increases your Ultimate's power by a lot and your auto-attacks are now ripping your foes to shreds.

All of Warwick's regeneration comes from Magic damage, so these will not only increase your movement speed(which is quite necessary), they will also make your passive, hungering strike and infinite duress heal for more and deal more damage, what more could you ask in a pair of boots?(Note: I do not know how Warwick wears boots, but he does love them.)

Attack speed=more passive procs=more survivability, movement speed=more kills and greater ease to escape ganks, Critical strike=tons of damage. This item is so strong on Warwick you need TWO of them, so you can run faster than the entire enemy team.

Your damage is already monstrous and your very presence should start instilling fear in the hearts of your foes, what does this mean? It means that since you are melee, you will most likely be focused in teamfights, this item protects against damage, thus making it easier to stay alive, and also gives you a second chance in a teamfight.

Note:if you notice you're being focused, do not use your ulti, wait until Guardian Angel revives you to use your ulti on someone about to die.

This item may at first not seem very strong on Warwick, however, due to it's passive and the 30 extra AD you get from it, it will make your a lot stronger, adding a total of 236 damage to it, which means this item boosts your ultimate's damage more than any other item in the game that would be useful for Warwick.
This item also grants a lot of other small but very useful stats such as crit, movement, attack speed, health and mana plus a slow, overall, a very strong item.

This item is VERY strong, it will make your attacks pack a massive punch, adding 160 damage to your ultimate and 80 to all your basic attacks, topping it off with a massive amount of crit chance and a passive that makes your crits become RIPCRITS!

Replace your doran's blade with this, it will give you 600 more health, 10 more damage and an on-hit slow which coupled with your movement speed will make it IMPOSSIBLE for anyone to escape you.

Warwick is known for being one of the champions with highest sustain in the game, which made him a very strong jungler in Season 1, though when Season 2 started, sustain stopped being important in the jungle, however, this build allows you to do some junglers's jobs better than them.
You can help your AP carry secure this buff with ease, whenever the chance presents itself incase you do NOT have a jungler, then secure it.

This guy is a lot harder, however, when you get your Madred's, you can kill this guy alone with no problems, be careful when doing this though, as the enemy team may ambush you while doing so, map awareness is key.
This guy is the icing on the cake, after you've bought your guardian angel, you should be able to solo him, now, you may be wondering what's the advantage of soloing since it takes a lot more time, well, it's a matter of fooling your enemy, because if they notice your team has disappeared from sight, they will most likely suspect you're trying to kill this guy, but if your team is visible and you are not, chances are the enemy won't suspect a thing whilst you're soloing the Baron, communication with your team is key when attempting this.

Be very patient when dealing this guy, he can easily avoid your ultimate by eating oranges, he also has a ton of movement speed and a lot of slows, but he is rather squishy under most circumstances.

He also possesses an ability to prevent infinite duress, shroud of darkness, it will block the next spell cast on him and then give him increased attack speed, which means if you use your ultimate when he casts the shroud, you will not only waste it, but also empower your foe.

He can make very clean escapes against you, because he is very tough and if you cast your ultimate on him, he can use his own ultimate unbreakable will to remove the suppression, take a lot less damage and then he will most likely headbutt you away, then he will shout: «MOOOOOOOOOOOOOOOO»

She deals a lot of damage and is quite squishy, BUT, her spell shield can block your hungering strike and/or your infinite duress.

She isn't a guardian angel, her black shield can block your ultimate, when you see anyone in her team with a purple shield , do not use your on them.

Be very patient when trying to kill this monkey, he can easily fool you and make you waste your ultimate on his Decoy, also, do not use your ultimate on him when he uses , it will knock you up right after you start channeling your , thus cancelling it.

From deceive to hallucinate, he can fool you with great ease, patience is key against him.

Be EXTREMELY careful playing against this madman, he can cast to remove the suppression from your ulti and deal so much damage with you will be dead before you know it, he also becomes a lot more dangerous when low on health! Making him very deceptive and powerful in 1v1 and 1v2 fights.

This may be a problem for many Warwick players, so here are my steps on how to fight in teamfights:

Step 1: DO NOT INITIATE, you have tremendous sustain through regeneration but you are extremely susceptible to burst damage. The only good Warwick is an alive Warwick.

Step 2: Do not attack tanks, offtanks or anyone who is tanky and can't be killed quickly, focus the squishy AD carries and/or Mages, basically, the squishier they are, the higher priority they have in your killing list.

Step 3: Save your ultimate to the teamfight-changing moment, this may be hard to understand, but what I recommend is this, after you killed your first target, use the ultimate on the second target in your priority list, or on the enemy who is about to kill one of your teammates, remember to use the Ripwick combo.

Step 4: Unless your team scored an Ace, chances are enemies will be at very low health trying to run away, remember your blood scent can give you the edge required to finish these opponents off.

Thank you for reading my guide on how to play Warwick, comments and votes would be very much appreciated, if you downvote then PLEASE, PLEASE leave a comment on what you think that should/could be improved.