Item Build

Starting Items

You will always be in the solo middle lane. Boots of Speed help you escape early ganks which are becoming more common in the newer meta.  The 3 health potions allow you to take quite a bit of harass during lane, this way you should be able to keep up in creep score. Starting with Doran’s Ring is an outdated build and does not work because it does not allow room for health potions, which are extremely crucial in extending your time in the lane. Starting with a Sapphire Crystal works as well, but the downside is that it makes you weaker in lane because you cannot avoid enemy harassment as easily.

Core Items

In the best of cases, you will go back to base for the 1^st time and purchase a catalyst right off the bat. What is more likely is that on your 1^st trip back you will have only enough to purchase a Sapphire Crystal and a Ruby Crystal. If that is the case stay in lane until you have earned 450g and go back when you deem it a desirable time to go back (lane is pushed, you just got ganked, or are low health) Do not build a Tear of the Goddess. If you choose this path, you will most likely be able to produce more damage than the Rod of Ages build but you have no items that give you any form of survivability, as well as being significantly weaker during the laning phase because you will not be able to abuse the Catalyst’s passive. Your next goal should be to turn the catalyst into a Rod of Ages, always. This item will give you mana, ability power, and health, and by which the way your passive works, magical damage mitigation.

There are a couple of items you should always buy on Kassadin, but there are some which tend to be situational. These items are Rod of Ages, Sorcerer’s Boots, and Rabadon’s Deathcap. Every game I get these items I feel I am using the champion to the best of his ability. You should not buy Archangel’s Staff because even though it does help your mana problems quite a bit, you will usually have blue buff, and the fact that the items simply offers mana and ability power does not help towards making you a tankier champion.

Endgame Items

Most Common Build

This is your most common build. I cannot stress how important the double Rod of Ages are. They make you a very tough target to kill and fight. Remember though that these items are very expensive, so be prepared to be on top of your game because you are going to need kills and/or an excellent creep score.  If the game is seeing a lot of team fights very early on, I would recommend actually skipping the 2^nd Rod of Ages and going for a Rabadon’s Deathcap. After that, you should buy a defensive item for the current situation. Good choices are Quicksilver sash, Banshee’s Veil, Zhonya’s Hourglass, Abyssal Scepter, and Guardian Angel.

Alternate Build

This build makes gives you over 3,000 hp, enough mana to sustain up to 9 stacks of Riftwalk (R), and almost 1,000 ability power. The only survivability you need is Zhonya’s Hourglass and Banshee's Veil. If you get outrageously fed, feel free to trade in your Sorcerer’s Shoes for a Lich Bane.