BOOTS

So, lets start with boots. Generally, you'll always want to have Dexterity boots, as they provide more attack speed, and that's kinda essential for a Marksman you know?

However, there are cases where these boots can be a bit hard to fit. So, say the enemy has way too much physical burst, you could instead buy Fortitude Boots, which will make you way tankier. Alternatively, if the enemy team has too much magic damage, or just a lot of cc in general, you can buy Resistance boots.

FIRST ITEM

Now, for your first item you have two options. You'll either build the vastly superior Shadow Ripper, since it gives you literally everything an crit-based ADC such as Luban needs. Ooooooor, hear me out, you could build Sparkforged Dagger and be a worse Di Renjie! For real, Sparkforged just doesn't help you with damage, especially since this item suits more heroes with a lot of mobility and move speed, both of which Luban doesn't have. I'd recommend sticking with the crit build I showed above, but if you reeeeeeally want to run the attack speed build, then here it is sweetheart:

SECOND ITEM

Now for your second item you'll most likely build Eternity Blade, since it is the item that will give you the most crit damage. Your damage wiill become more noticeable now at this point. If using attack speed build, you'll build Shadow Ripper for even more attack speed.

idk, this part is kinda short. Blade just helps too much with damage output and Ripper is just a good item soooooo you'll build them early.

THIRD ITEM

Your third item in most cases will be Bloodweeper, since it helps soooo much with sustain and general survivability.

However, if the enemy team has too much lifesteal to the point where you also have to build anti-heal, instead of weeper you'll build Mortal Punisher instead. However, I highly advise against this as Bloodweeper is way too good of an item to pass up and Punisher is a straight downgrade, and it's better for your mage or support to build anti-heal. Only build this if your team is being stupid, is what I'm trying to say.

HOWEVER, if you use the attack speed build, Mortal Punisher becomes a more attractive option since it also gives you attack speed. So if running that build and the enemy team has a bunch of lifesteal, build it instead of Doomsday.

FOURTH ITEM

For your forth item, there is a bit more debate. Why? Because people can't decideffor the love of god whether to build Daybreaker or Starbreaker.

But, worry not, for I, the bearer of all truths, have the answer...... drumsrolls please.....

It's Daybreaker and it's not close.

While yes, Starbreaker does have higher over-all damage, it isn't consistent. The reason being that if you do opt to go for it, you'll be sitting at around a 60% crit rate, so you'll notice that your damage will flunctuate a lot. Sometimes you'll be melting people, sometimes you'll be doing no damage (Because you aren't criting).

Daybreaker will leave you at about 70% crit chance, making it waaaay better. You'll do only slightly less than a highrolling Starbreaker and at a much more consistent pace.

FIFTH ITEM

This is the flex item, here you can build whatever you want and feel most comfortable with or change depending on Match-ups. If you need raw damage, build Siegebreaker or Doomsday for more tankier threats, if you want more sustain, build either Succubus Cloak if the enemy has a ton of magic damage, or build Ominous Premonition if the enemy has a lot of physical damage.

Keep in mind that if you need an active item, you'll always build Pure Sky. I know, strange, especially for a Marksman, but hear me out. This item makes it so you'll can actually stand still and deliver maximum damage without worrying about getting bursted down, so it is quite good actually. Now you may ask, "well why not build Sunchaser since it's designed for Marksman" and the reason for that is, while his normal basics attack will benefit from the range boost, his enhanced basic attack won't, still having the same range, so pure sky just allows for better damage output and sustain in one item.

As a last tidbit, I highly reccomend getting at least one sustain item, Luban No.7 just becomes way too fragile without one, so keep this in mind.

LATE GAME CONSIDERATIONS

You should be full build and have some spare gold by now, so I would also recommend to sell your boots and to build either Sage's sanctuary or Destiny (Sage's sanctuary is the priority, build destiny when it is on cooldown or not avaiable). Also, buy the upgraded version of Pure Sky called Sky Dome.

phew