_{Ability Power or AP is one of the two core offensive stats for increasing damage in League of Legends, serving as the counterpart to Attack Damage. But while Attack Damage is fairly straightforward in gameplay as the unmodified amount of physical attack damage, its counterpart is a bit more complicated.}

We'll go over what AP does and how you can harness its full potency to maximize your performance in the game.

How Increasing Ability Power Works

AP has no baseline effect on its own; instead, each point of ability power increases the damage, heals and shields of any ability that scales with AP, as shown in its tooltip. But because every champion starts out with 0 ability power, you will have to work on building the stat up through items that grant AP, runes, and in-game buffs.

When building up AP, each item's bonus AP stacks additively with your existing total. Whatever total AP you have is multiplied by the AP ratio of an ability or skill. For example, even 100 AP from one item already boosts a spell with a 0.6 AP ratio by 60 points, and if you have a base AP of 300, you're getting 180 bonus points of damage or effect (health recovery, shield value, etc).

AP vs. Attack Damage: The Core Difference

An AD champion's damage dealt is mostly through basic attacks and physical abilities, while AP champions, or mage-type champions, rely on mana or energy to cast spells, with AP damage typically coming through as magic damage. As for damage mitigation, Armor reduces physical damage from AD, while stacking magic resist on the enemy's side is the defensive answer to AP-scaling abilities.

Considering the nature of AP, this means some champions like Darius or Zed don't really benefit from stacking AP, and decreasing ability power on their builds costs them nothing, since their attack effects and physical abilities scale off AD instead.

Top AP Items at a Glance

Item	AP	Unique Passive
Rabadon's Deathcap	130	Increases total AP by 30%
Shadowflame	110	Bonus magic penetration
Luden's Companion	100	Damage bounces to nearby targets
Void Staff	95	40% magic penetration
Malignance	90	Ultimate ability haste
Lich Bane	90	Empowered basic attack after casting a spell, plus movement speed

AP Scaling Through Runes and Abilities

Since many abilities scale off of ability power, raw AP from other sources beyond the fixed amounts items grant also matters, especially in the late game when scaling ratios compound. Some runes grant AP, such as Absolute Focus, Conqueror, and Adaptive Force shards. Veigar is a special case as a champion that can stack AP with his passive ability, Phenomenal Evil Power, which lets him stack over 1000 AP in a match, and Mejai's Soulstealer works similarly by granting stacking AP for kills and assists.

Stack Smart, Hit Harder

Knowing about AP is step 1, but there's more to this, and choosing the right ability power items for your champion's scaling ratios and your team comp is more complicated. If you feel the need to level up your AP mechanics, BoostRoyal's LoL coaching will pair you with experienced players who know their way around builds and more. You can also get a ranked-ready account to test builds without risking your main.