Heart of Gold first for money because farming with Rammus can be slow. Some people like to grab Boots of Swiftness because Rammus can be slow but the benefits of Mercury Tread's out weight the speed increase that Boots of Swiftness gives you. Plus Powerball should give you enough movement speeds to get to anywhere you want.

I like to get Warmog's Armor after boots for the mid game health survivability. Warmog's Armor is bought relatively early so you can start building on the health bonus it gives. Even though you haven't bought your Thornmail or Force of Nature, a maxed out Defensive Ball Curl will help you survive most fights.

Can interchange thornmail or force of nature buy order depending on champions you face.

Can put skill points in defensive ball curl first for survivability. Only need one point in powerball for map movement and ganking. Great for tower defense if you max defensive ball first. If there are 2 or 3 champions that are attempting to take down your tower, right before they begin attacking the tower, hit your defensive ball, taunt, and hit tremors. If they start running, give chase and allow your tremors to damage until it stops. If you taunted the squishy melee character they should be low health. If your defensive ball and taunt are back up and have enough health, powerball and go for the kill. This tactic is viable midgame and up. Early game is just about harassing laners using your defensive ball and not allowing them to get last hits. If you maxed out Defensive Ball Curl and have Warmog's Armor you can go one on one with almost any character and they will run after trying to kill you because they just can't hurt you. The 150 added armor and magic resist is just to great for any champion to overcome.

Powerball then flash over minions is a great way to close the distance. When you're getting ganked, I recommend going defensive ball curl, running away, and soon as it's done, flash and powerball run.

This build is all about survivability. End game with all the armor and magic resist coupled with the defensive ball curl, you cannot be killed. In group fight if you successfully initiate and taunt the squishes and let your teammates do the rest, it'll end up with you team on top. Tower diving is just too easy with this build.

Remember you're a tank and meant to take hits and you should usually be the one to initiate in team fights. Defensive ball coupled with thornmail and taunt will decimate DPS melee characters like Tryndamere or Master Yi. I always buy Negatron Cloak first when building my Force of Nature likewise Chainmail when building Thornmail. Powerball is also great for fakeouts. If you're in a team fight and not confident that you'll win the team fight then begin your Powerball and act like you're going for a team fight initiate. This will cause them to hesitate to fight and give your other teammates some time to get to the fight.

As far as champion spells goes, flash is a must for easy escapes like I explained above and also those surprise Powerball ganks when you flash over mobs or just flash and get a direct hit. I like to get teleport so I can defend a tower if I can't get there in time with my Powerball alone. Usually with Powerball you can get around the map pretty quickly but sometimes when you're laning in a bottom or top lane and you see that the opposite tower is about to get attacked with no teammates near by, teleport and use the strategy mentioned above if the other team decides to stay and try to take the tower out. I don't recommend getting ghost because of Powerball. You can interchange teleport for exhaust or ignite but I like the added flexibility to get around the map with teleport and the ability to be able to defend a tower at will. Also, you have a ward in the bushes or a Teemo mushroom, you can teleport to the location and it's a great set-up for a gank.

If you are relatively close to a champion that you are going to gank judge the distance it takes for a Powerball run to hit the champion. This means that the distance travelled when you hit Powerball and when the skill runs out. It is a good way to get a jump on your enemies. Another good strategy is as you hid in the bushes, let your Powerball build speed till about half way or three quarters of the way then start chasing. You should be too fast for them to run. If they flash away then this is the perfect chance to flash/Powerball them. After you hit them with your Powerball, taunt and hit defensive ball, then hit Tremors. You'll take little damage and they'll be running. Continue to chase so your tremors damages them. If you're defensive ball curl is still up and have enough health, don't be afraid to give chase if they hide behind a tower if it means a kill. If you get in a pickle and you're about to die and still have your flash then you can easily flash out and Powerball run away. Rammus is one of the best at running away to save your life.

Hope you enjoyed my ramblings on Rammus. I know it's not organized neatly. It's just my thoughts on how to play him. The item building and purchase order is key to playing this type of Rammus.