Mechanics: Spell Vamp

Spell Vamp is an odd mechanic because it has a bunch of confusing rules as to its application. These rules have confounded and confused the community for some time because whenever someone asks, "Does Spell Vamp work on insert ability here?" they get 20 different answers. I hope to do my part in raising the general awareness of Spell Vamp's mechanics today.

Spell Vamp is actually a bit of a misnomer. "Spell" for many players implies "magic", and so they reasonably assume that Spell Vamp only works on magic damage. This is not the case, as Spell Vamp works on all cast abilities regardless of damage type (otherwise what would the point of Spell Vamp on Olaf or Lee Sin?). A more accurate name would be Ability Vamp, but Riot has never seen fit to change it.

So everything from Reckless Swing, to Noxious Trap, to Resonating Strike can make use of Spell Vamp, but there's plenty more confusion to be had. Spell Vamp's effectiveness is reduced by two-thirds on multi-target abilities. This is a necessary mechanic because otherwise a Morgana with no Ability Power at all could heal for 500+ Health with a single Tormented Soil. Still, it's something else for players to remember about Spell Vamp.

More confusion abounds because of Smite and Ignite. Because they are coded like abilities they actually work with Spell Vamp. You can, to this day, find threads where people ask whether these two Summoner Spells work with Spell Vamp, and get multiple answers. Rest assured, Spell Vamp definitely works with both (though it can be hard to notice for Ignite as its damage is done over time).

Then there are items like Hextech Gunblade and Deathfire Grasp. These too use Spell Vamp because their actives are also coded like abilities. These don't come up as often as Smite and Ignite, but they have classically been a point of confusion.

While damaging item actives do make use of Spell Vamp, on-hit effects from items do not. However, champion on-hit effects aren't so well delineated. Because the "on-hit" effects for many champions use backend code tricks to function, a number of them do work with Spell Vamp. Rather than have me list them all, you should refer to this list on the LoLWiki. When in doubt, you can always run your own tests, and then update the wiki as necessary.

As an aside the most Spell Vamp any champion can have in the game is 244.7%. It requires an Akali with 6 Gunblades, stacked buffs and is generally utterly implausible, but it's fun to imagine Akali Smiting something and healing for 2400 Health. A much more reasonable (relatively speaking) number is 153.5% (5 Gunblades + Runes/Masteries). It's overkill, you can solo Baron at 2 Gunblades, but it's fun overkill.

Hopefully that made Spell Vamp's mechanics slightly more clear. There are a lot of misconceptions about the mechanics of League of Legends, and while they may never be eliminated if I can reduce the cacophony of errant answers even slightly I'll be satisfied.