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Mage Optimization Tool

AP Calculator

Calculate your total Ability Power with items and runes. Understand spell scaling, Rabadon's multiplier, and optimize your mage build for maximum damage output.

Quick Start Presets

Select Champion

Select Boots

Select Rune

Select Items (Max 5)

Selected: 2/5 items

Your AP Output

Total Ability Power
284
210 base + 74 Rabadon's
Items AP
210
Rune AP
+10
Spell Damage*
+170
Build Cost
8,100g
Rabadon's Active

Your AP is multiplied by 1.35x. Bonus: +74 AP

Build Summary

Champion: Average Mage
Boots: Sorcerer's Shoes
Rune: Sorcery (+10 AP)
Items: 2/5
• Luden's Echo
• Rabadon's Deathcap

Quick Tips

  • ✓ Rabadon's is your strongest scaling item
  • ✓ Mythic item is usually your first
  • ✓ Void Staff for magic resist shred
  • ✓ Always include a defensive item
  • ✓ Spell scaling varies by champion

* Damage increase assumes 60% average spell scaling

Understanding Ability Power

What is Ability Power?

Ability Power (AP) is a stat that increases the damage of your champion's abilities (spells). Different champions have different base AP values and receive different amounts of damage per point of AP. For example, Ahri's Q ability deals 40% of her AP as damage, while other abilities might scale at 60% or higher.

Spell Scaling Explained

Each ability has a scaling coefficient shown as a percentage. A spell with 70% AP scaling deals damage equal to (70% × Your Total AP) plus its base damage. For example, with 300 AP and 70% scaling, that's 210 damage just from AP scaling, not including the base damage.

Spell Damage = Base Damage + (Spell Scaling × Your AP)

Rabadon's Deathcap Multiplier

Rabadon's Deathcap is the most powerful AP scaling item in the game. It provides 120 AP and increases your total AP by 35%. This means if you have 300 AP from other sources, Rabadon's makes it 300 × 1.35 = 405 AP. This multiplicative effect is why it's almost always a core item on AP mages.

Item Types and Their Purpose

Burst Mages

Luden's Echo, Rocket Belt, and Shadowflame for one-shot combos

DoT Mages

Liandry's Torment for sustained damage over time

Scaling Items

Rabadon's Deathcap for maximum AP multiplier effect

Support Items

Zhonyas, Void Staff, and Morellonomicon for utility

Build Optimization Tips

  1. 1.
    Buy a Mythic First

    Mythic items provide the most AP and utility. Choose based on your playstyle and enemies.

  2. 2.
    Prioritize Rabadon's Second or Third

    Rabadon's multiplier scales with your total AP, so buy it after gaining some base AP from other items.

  3. 3.
    Consider Magic Penetration

    Void Staff or Sorcerer's Shoes help against tanky opponents with high magic resistance.

  4. 4.
    Balance Offense and Defense

    Include at least one defensive item like Zhonya's Hourglass to survive burst damage and crowd control.

  5. 5.
    Adapt to Game State

    Build according to enemy team composition. More AP for squishies, penetration for tanks, utility for teamfights.

Frequently Asked Questions

How does Rabadon's Deathcap work exactly? ▼
Rabadon's Deathcap provides 120 AP and increases your total AP by 35%. The multiplier applies to all AP you have, including base AP, runes, and other items. For example, if you have 200 AP from items and runes, Rabadon's gives you 120 AP plus (200 + 120) × 0.35 = 112 additional AP, for a total of 432 AP. This makes it the strongest scaling item in the game.
Should I buy Rabadon's first or second? ▼
Generally second or third. Rabadon's multiplier is most effective when you already have AP from other sources. Start with a Mythic item for utility and base AP, then buy Rabadon's to amplify your existing AP. Rushing it first means you miss out on the multiplicative benefits since you have less AP to multiply.
What's the difference between Luden's and Liandry's? ▼
Luden's Echo is for burst damage mages who want to one-shot enemies with quick combos. It provides instant burst procs. Liandry's Torment is for damage-over-time mages who deal sustained damage through multiple ability rotations. Choose Luden's for assassin-style play and Liandry's for poke and sustained fights.
When should I buy Void Staff? ▼
Buy Void Staff when enemies have built significant magic resistance (MR). Generally, this means third or fourth item. If you're facing tanks stacking MR, buy it earlier. Against squishy teams with no MR, you can skip it or buy it last. The magic penetration becomes more valuable the more MR your enemies have.
How important are runes for AP builds? ▼
Runes provide modest early game AP bonuses. The Sorcery tree AP bonus gives 10 AP, while Transcendence can provide up to 15 AP through cooldown reduction conversion. While not massive, every bit of AP counts early game and scales with Rabadon's multiplier later. Choose runes that complement your playstyle and champion.
What's a good target AP number for late game? ▼
With a full build including Rabadon's Deathcap, aim for 500-700 AP. With Rabadon's and 4-5 other AP items, you should easily reach 600+ AP. Remember that more AP isn't always better—you also need magic penetration, cooldown reduction, and defensive stats to be effective in teamfights.

Master Your Mage Builds

Use this calculator to experiment with different item combinations and understand how AP scaling works. The more you practice, the better you'll become at optimizing your builds for different game situations.

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