Spell vamp / Life steal and AD scaling abilities

Question

What do AD scaling abilities scale on for leech effects?

Take the following skill for example, it is pure AD scaling:

Lee Sin

Spell Summary Sonic Wave: Lee Sin projects a discordant wave of sound to locate his enemies, dealing (50/80/110/140/170) (+(1 per attack damage point)) physical damage to the first enemy it encounters. If Sonic Wave hits, Lee Sin can cast Resonating Strike for the next 3 seconds.

Resonating Strike: Lee Sin dashes to the enemy hit by Sonic Wave, dealing (60/90/120/150/180) (+(1 per attack damage point)) physical damage plus 10% of their missing Health (Max: 400 damage vs. Monsters).

What would I leech health back from?

• Life steal
• Spell vamp
• Both
• Neither

Answer 1

Life Steal and Spell Vamp don't proc based on the damage bonus source of the skill (AD versus AP), nor is it based on the damage type (physical versus magical). It's actually based on the kind of skill.

In general, Spell Vamp is the only drain effect that affects skills. All of Lee Sin's skills, despite all being AD-based physical attacks, use Spell Vamp and Spell Vamp alone. Akali is an example of a somewhat physical champion whose attack skills are all Spell Vamp-based (her innate Life Steal is to benefit her auto-attacks only). Even skills like Ashe's Volley, which applies her Frost Shot effect (but only that, the key point being as you'll read up soon), will use Spell Vamp.

Life Steal generally applies only to your auto-attack, but it also applies to skills that apply on-hit effects. For example, Blitzcrank's Power Fist deals 100% extra damage and pops the target in the air in addition to applying on-hit effects (for items like Black Cleaver). This benefits from Life Steal instead of Spell Vamp. Other examples of skills that benefit from Life Steal would be Irelia's Bladesurge, Ezreal's Mystic Shot, and Gangplank's Parrrley.

As far as I know, there is no skill which benefits from both Spell Vamp and Life Steal. It's always one or the other.