Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
In this build, Rammus is built as a tank. This is the best option because he does more damage with more armor. Contrary to my other Rammus build, this one helps you out more in early game. Rammus is attacked a lot so the start boots help you to get away. Giant's Belt is essential. Get it fast. Farm gold as bes as possible. The health you gain is so good, it literally makes it at least twice as hard for you to die. Also, level up Tremors as fast as possible. You want Defensive Ball Curl fast too, but you want the damage from Powerball first. This will help keep the other team away from you and the other person in your lane and help you gain experience and gold faster. Defensive Ball Curl will give you more damage, less chance of dying and if you pair it with ult, or alone for up to level 6, it works great against turret. Puncturing Taunt you want before Defensive Ball Curl because you can taunt in and punish them and also, after Defensive Ball Curl, you can make them hurt themselves. You can use Powerball for chasing, slowing, stopping ultimates like Katarina's, or just as a power punch to help you get a kill. Your ultimate can be used at almost any time. Use it in a mass of minions to get lots of gold, use it to get kills that you want to be fast, if you just can't kill the other person without it, to do area damage in team fights or to do tremendous damage to turrets. Many people may think that Rammus is a noob champion, but they would be wrong. He is versatile, but can be taken out by large damage, high armor penetration champions or high magic, high magic penetration because of his lower magic resist. Neither of these are always true and many times I have had kill sprees really early game, but you should take them into consideration. Happy killin'.