Due to his base armor and armor increase per level, Rammus effectively receives a bonus to his base attack damage (~5) and additional attack dmaage per level (~1) up to a ~21 bonus attack damage at level 18.
Any buff or debuff that affects Rammus' armor will increase or reduce the bonus damage respectively as well. (e.g. Bulwark or Spirit Fire)
Similarly to Galio'sRunic Skin, Spiked Shell will cause a decrease in attack damage if Rammus' armor is reduced below 0.
Cost: 70 / 80 / 90 / 100 / 110 mana
Active: Rammus enters a rolling ball state for up to 7 seconds, constantly accelerating from an initial bonus 3% move speed up to a bonus 165% move speed. While in this state, Rammus cannot attack or use Puncturing Taunt. Activating Defensive Ball Curl or re-activating Powerball during its duration will end the effect instantly.
Upon colliding with an enemy unit, all nearby enemies are briefly knocked back, take magic damage, and are slowed for 3 seconds afterwards. Rammus reverts to his normal state as well.