Leech mechanics explained with examples

There has been a lot of confusion about how the new leech mechanics work, so I wrote up a page on the wiki: http://pathofexile.gamepedia.com/Leech

If you see anything that looks incorrect, please let me know. You can also just edit the page if you have a Curse account.

Great work! Cleared up a few things as I was unsure how leech worked now after the changes.

It's more nuanced than you make it out to be, especially in the case of attacking with multiple projectiles, where the more you divide up your damage (eg with chain) the less you end up leeching - unless you can somehow get the projectiles to all hit at different times.

Put in simpler terms: all things being equal including total damage dealt, if you hit two targets at the same time for half the damage, you leech half as much as if you hit only one target for full damage.