The key to the build is to make a Rammus who is very much a ridiculous tank. The single most important thing is to be able to get kills and assists with Leviathan. It seems a little cliche'd to get kills with a tank, but while you're going you'll get kills thanks to his passive he'll have a load of attack damage combined with tremors, his taunt, shield and thronmail will kill a lot very fast.

It is rare to find a character who can play a leviathan build well, but if you're careful with Rammus and if you're team can deal enough damage it is very easy to get a lot of assists and kills and achieve the -15% damage taken from getting 20 stacks with the Leviathan.

This is the general item set, for teams with 2 AD + 3 AP/ 3 AD + 2 AP or 2 of each + 1 support.

If the other team has 4 AD champions:

After getting leviathan get thornmail, then guardian angel then Banshee's vale, then grab frozen heart.

If they have 4 AP champions:

After Leviathan get Banshee's vale, then guardian angel, then thornmail, then Force of nature.

Teamwork is very crucial for this build. Although it is faster to build stacks with kills you will get most of them from assists. The key is to initiate with your roll, then tremor, then taunt then shield. You'll do massive damage and single out one of their members to kill and do a load of damage and shortly after you can roll again into the foe. Rinse and repeat until you run out of mana.

Pros:
- With your over 3k health + 18% less damage taken from masteries and leviathan. As well as about 70% reduced from your Magic resist and armor + guardian angel being able to bring you back up you are very hard to take down.
- With all of your armor Rammus gains a load of Attack damage + his abilities do a lot of damage + Thornmail, your shield and taunt makes Rammus very dangerous as far as damage as well.

Cons:
- You are very dependent on Leviathan and your team's success.

The way to fight, kill and destroy as Rammus. Roll to initiate, set off tremor, taunt and shield. This'll do optimal damage and allow you to quickly roll again into the next foe.
The single most important thing to do is to choose your battle carefully don't get outnumbered by the enemies unless you have backup in toe. Which should help you maintain stacks and will allow you to do your job late game.

This type of Build can be very hard to play especially when your team isn't doing well, but don't fret. As long as you're careful and spend early and mid games playing smart you shouldn't be doing very badly even against a very fed team.

A player who is good with his roll and taunt and tremors and shield will easily and quickly reach full stacks with Leviathan and find yourself very difficult to kill and a very powerful asset to your team.

Just remember that you shield will increase your AD so make sure to it offensively as well as defensively. Your shield can be very helpful against enemy towers.

At the start of the game you really want to lane with an AD champion so you can quickly push out damage to get Leviathan sooner. Usually you can't do enough damage to make a large dent in your foes until you reach level three and have your shield and taunt. It isn't a bad idea to occasionally roll into minions to get a few more minion kills if you find yourself low on minion kills. You don't need minion kills to get going, but it helps. More money means faster Leviathan. If you aren't getting many minions kills buy a heart of gold to help getting your other supportive resistance items. You shouldn't have to return to Base until you reach level 6, but if you do you may want to consider buying more potions so you can survive and prevent yourself from becoming dead.

Once you reach mid game you should have Leviathan and guardian angel, which is a wonderful way to help maintain your stacks. It'll also give you a moment to get the enemy by surprise with another roll and do more damage which should help your team destroy them in team fights. With the power and speed of Rammus when he is using his roll you can easily gank enemies when they're trying to farm and should be able to take them out with no problem.

If you notice that your team isn't doing so well just pick your battles well, if you see a team mate who is fighting multiple enemies at once don't go in unless the enemies are doing poorly. In all likelihood a team mate fighting 2+ enemies'll soon be fighting many more and you going in will not help them survive will only kill you and make you less difficult to kill.

By Now you have full Leviathan, Guardian angel, thornmail, and probably Banshee's vale. You'll notice that the other team is having one hell of a time fighting your team with you singling them out and them being unable to kill you. You should be able to help you team roll over your foes and win the game without too much trouble. Teamwork is key late game, stick with your team and don't get over confident with your crazy tank abilities and you guys should do just fine.

If your team is doing poorly and the other team is fed do not fret. Just be careful to taunt the foes into towers and exhaust them there this'll allow your team mates to do damage and should help you get assists doing this enough should allow your team to start gaining momentum and can even turn the game around.

This build is make Rammus into the super tank we all always knew he was. With Leviathan as the center point to this build you always have the worry of dieing and losing your stacks, but at the end of the day the most important thing is to help your team win. With a full Leviathan Rammus gains 840 HP, and reduces damage taken by 15%. Anytime your champion takes a lot less damage and has a lot more health it becomes more and more unable to be killed. Throughout the game as you gain stacks the mere health bonus Leviathan gives you you'll notice Rammus becomes much harder to kill.

Whether your team is doing well or not, whether you have a bunch of stacks or not this build is still very capable of tanking and can be very helpful against any foe.