Hello guys! My name is Nick, but my league account names are thezacisback and lucario200151 (lost password to lucario200151 and unable to recover). I am a silver 3 player that mains jungle and mid. I have about 75k or so on Rammus so far, and plan to play him more so that I can update this guide to the next level. Rammus is a fast champion that can win any fight late game!
Anything I can do to improve this guide? please email me @lucario200151@gmail.com for suggestions!

pros

Late game monster
fast with q
taunt will make them take damage with w
some nice tank stats while in w

cons

not as tanky when not in w
w slows him
should only be picked into physical damage teams as mr doesnt go well with him
kind of weak early on
must stack armor and build thornmail to win.

this is how we max rammus, and we take e at level 7 for the extra taunt time and attack speed, because it is last to max.

Passive: Spiked shell

This is where the damage starts... The w goes based off what the damage of this is, and amplifies it. This makes your auto attacks do more the more armor you have. That is also bad, because it means to get the max out of it, you must build full armor.

q: Powerball

This is where your great combos start. Sometimes, you will have to flash q to get the knockup off, but it is worth it. This ability makes you fast, so you can easily get places fast, but it has a strange hitbox that takes some getting used to.

w:Defensive Ball Curl

This is going to be where the damage comes from. This gives you more tank, as well as amplifies your passive by 150%! This makes it so that he is the ultimate counter to strong auto attack champions like Tristana and Ashe.

e:Frenzying Taunt

This is how we "enforce" damage on someone. This provides for a good taunt that can last for one, two, or possibly 3 auto attacks. It also gives you a decent amount of attack speed, making it so if they are near, you get your w off more.

Ult: Tremors

Compared to other ults in this game, this is not an essential part of the kit that Rammus has. It is just here to support you and help to deal damage to enemies and turrets in range. I feel that this should be changed to something that goes better with the rest of his kit, but for now it works. it is a good way to ensure you outduel melee champs.

These are the runes I take and I will explain why

Resolve

Aftershock

This is a very good rune to take on rammus, because it pops upon ramming into someone with your q, which means that without a dash, the enemy is guaranteed to get hit by it. It makes up for your early damage being low to an extent, and is my primary go to when I play most tank junglers.

Bone plating

This rune will level out your early game a bit by giving you some damage reduction so that you can get more damage off and possibly secure a kill. This will overall enhance early gameplay by quite a bit.

Conditioning

This rune will enhance your late game damage by a noticable amount. It gives you armor, which scales with your passive to give your w more damage to kill them.

Overgrowth

Some may tell you to go unflinching instead, but I feel that overgrowth is better, because unflinching just gives you tenacity, which could make you move a bit faster with w, but overgrowth gives you more health to survive longer in a fight where you are going to need it!

when to pick

heavy auto attack enemies
low mobility enemies
physical damage teams

when not to pick

high mobility enemies
magic damage teams
tanks

There are 2 summoner spells I would take on Rammus

Flash

Flash is taken for escapes late game considering you have low mobility without q, and it is also taken so that early game, a good gank would consist of flash -> q(going to have a video of it below in gameplay section)

smite

Smite is taken on all junlgers. You get more exp, and you can take things like drag without your teams help, and you can ensure that you get it, because of this spell.

vs

In the case of Rammus, I feel that hunter's talisman would be the better pick, because his w does damage to everything that attacks him, and talisman does damage to what you attack, so since your w counts as an attack, you essentially take damage to deal damage(that's what Rammus is about)

The winner(what you should take)

Stalker's blade - Cindehulk

Considering the fact that Rammus is a tank, this item is good for multiple reasons. It goes well with your kit, as it deals damage to anything near you, and since you have w, that means more damage while being tanky!

Thornmail

This is the core item on Rammus. If you have to miss out on this because of a magic damage team, that will greatly hurt you, because this gives you part of your core damage. This item will proc at the same exact time your w procs, making it an amplifier to your w. Build this second. With the cold steel passive, it will reduce their attack speed a bit, but the damage you get from this item makes up for it.

Warmog's armor

A lot of people are probably asking me why I don't go armor next, and that is because even on teams you pick him into, there is that one magic damage enemy that will deal damage to you. This item will make up for that. It will also help you survive in a long fight with the other champions, and in my opinion, this item provides more defense than armor does! It also helps you heal while out of combat with enough max hp, so build this third.

There are 3 boots you could build

Boots of swiftness

Build these in most of your games. They are a great item to help you with your Powerball max speed!

Ninja tabi

Build these if you see that the auto attack champions you want to target you are going to be ahead. This will make them do less damage to you, making it so that it is easier to deal more damage to them.

Mercury's treads

Build these if you feel that heavy cc has caught you off guard, and you need to get out of it faster, as well as having a magic damage defense.

Dead man's plate

This is another good item on Rammus, and I would look to build this if there is a chmpion that is hard to get to, and you need that extra movement speed with Powerball. This item also goes well with all the main parts of you, so it is going to provide you with more to your damage as well as to movement speed.

Frozen heart

I would look to build this as a defensive item. If you are far behind, build this, as it gives you the most armor in the game, and reduces their attack speed by 15%! You don't build this, because it makes it more likely that they will quit attacking you after a few autos, but it makes you deal more damage to make up for it.

Gargoyle stoneplate

This is a good item to build as heavy defense. It provides you with more health when you activate it, making you a more difficult target to kill, but it will decrease your damage significantly. Build this in an emergency where you are going to die really quick.

Locket of the iron solari

This is an item that provides you great tank stats, and has a passive that makes you and your team live on another minute in a fight! If you use this, your w will continue to deal damage, and you will possibly be able to win a fight, because of it!

Randuin's Omen

With the crit adc meta being gone for now, this item is not that great of an item to build. You already have cold steel from Thornmail, so it is even less of an item to build. However, there still are very few champs that go crit ad, so build this to give them an even harder time!

Righteous glory

This is another item to be build with Dead Man's Plate to help you track down the harder targets to catch. It also slows them, making it a great item to keep them near you!

Abyssal mask

Build this if the enemy team has strong magic damage, and you have magic damage on your team. This is to be used in an emergency, as it does lower your max damage by a considerable amount(considering it's not armor).

Adaptive helm

This item is to be used only in an emergency! It makes your damage output lower, and should only be built if someone, like Karthus, gets ahead, and you need to build against them.

This is where certain combos that we use will be used. Before we talk about those, let's talk about jungle pathing.
My most common jungle path is
blue buff
gromp
rift scuttler
gank(if you can)
wolves
red buff
raptors
krugs

That is my most successful path.
Now, let's talk about early game combos.
We have the q->flash combo(as shown in video in practice tool)
Play Video

This point and the late game are very simmilar. The mis game is about going up to someone, and taunting them with w and ult to deal lots of damage! You basicly do the same thing late game in a fight to make it so that a carry does not get to target the rest of your team! For the most part, you want to stay grouped with your team, and let them target the other enemies. You get the one who you taunted!
Below is a video of late game Rammus damage(after i find a good game and record it)