Board Thread:Wiki discussion/@comment-4881935-20130327060139/@comment-3974211-20130327161638

I agree with Krufix.

Diameter is ground-targeted AOE, whereas Radius/Range is anything that is centered on a champion. Although I disagree with the distinction based on size - Trundle's should still be a diameter.

Although, I was of the understanding that the "radius" of self-centered AOEs were drawn from the champion's edge, not from the champion's center. As such, the "diameter" of things such as Amumu's Despair changes if he has Lulu's Rampant Growth - but the Radius stays the same. This is done so things like Sunfire Cape, Randuin's, Shard of True Ice, etc, aren't less useful on big champions (since I'm fairly certain Strom Shielded, 6 stacked, Lulu'd Cho'Gath is the size of Sunfire Cape's aura on Teemo).