Hello, This is my first Guide on mobafire and im showing you the build which brings me to victory, whilst playing Darius.

5 attack damage Marks and 4 Magic penetration The reason for the Magic Pen is because it works well with has Passive which scales of AP so I pick up 4 Marks just for the early game harass.

9 Flat Armour Seals for the early lane sustain as I take boots and 3 pots.
9 Armour Glyphs just for the extra armour, which helps me vs early game champs.
3 Quints of Physical Damage of course for the early Damage vs your Opponent.

The masteries I take are 21/9/0 21 in Offence/Offense in this i do Not! Get the 3in life steal as i believe it is useless on darius as he scales of his combo E,W then AA to low hp Q when they run so they are in the outer layer of your Decimate dealing 50% more damage and then using your ultimate which deals more True damage with the more Stacks on your passive. and I take 9 in Defence/Defense fore the extra 30hp and health regen whilst laning.

I start with Boots and 3 pots for the obvious reason of, more sustain via the health pots and the boots for faster movement if you get ganked by the opposing jungler, it also helps get around for the last hitting and warning your enemy away. From minions. Then once I have picked up enough for a Phage, I will then recall and purchase it with 2 Green Wards; This is because now you have the Phage you want to be more aggressive and win the opponents tower whilst being aware of their jungler so I would recommend warding the river opposite the T brush and also inside the T brush for the early awareness of being able to get back to your turret. Then once I have enough I get my Mercury Treads for less tenacity whilst laning against someone with a silence or slow etc... Also for the reason of mid lane possibly ganking you so this will help with the Magic Resist. Then I build towards my trinity force next picking up the sheen then , zeal last as the attack speed is not as useful as a sheen on darius. Once I have my trinity force i usually ask my jungler for our Blue Buff because the cool down reduction is insane on Darius then I usually invade the enemies red buff, then if not done so already I would recommend killing dragon for the bonus gold and then stay out of lane and try picking up some kills. After this I tend to have enough for my Giants belt or even being able to buy my warmogs right away, after my warmogs I get Atma's impaler for the extra armour and attack damage increase with my health , this scales nicely giving me a fair ammount of damage and armour. After this I build straight into my hexdrinker for the shield protection on their midlaner who will be dealing a lot of damage. Then I get my pick axe build into a Maw of Malmortius giving me more magic resist and a shield absorbing magic damage after taking a lot, also it gives me 55 Attack Damage which is even more helpful being able to defeat my enemies faster, after this you can build another situational item or I tend to build a Randuins Omen for the reason of more armour and more health which also gives me more damage from my Atma's impaler, and thats where I finish my build it is such a strong build late game or if fed mid game also with baron nashor the damage is amazing, Remember to always pick up enemy of ally buffs when possible.

I put a point in Decimate first as it gives darius a larger range of harass on the opponent also as it helps get more than one minion at a time. Then I put a point in Crippling strike Nd then apprehend this is so that I am open to all of darius's abilities. Then I try to max my Q as soon as possible which gives me more damage and is able to poke enemies easier. Then I max my W for the extra damage, and lastly Apprehend for late game as not many champs build a lot of armour early game as it gives armour penetration and pulls the enemy, for close rage attacks, and of course maxing your ultimate when possible.

For summoner spells I take Ignite and Flash because flash deals true damage and so does my ult and it is easier picking up kills using ignite then my ultimate. And of course I take flash for the only escape route which darius is available to.

Pros

With the runes and masteries good sustain and a lot of harass early game.
Very fun to play with, as you warn enemies away from minions.
Easy to get first blood and dominate your lane with a early gank from your jungler.

Cons

He can also be harassed whilst decimate is on cool down.
No escape ability so you have one chance to escape perfectly with flash.
Can be squishy.