Spell areas and large creatures

[sierzadon]

I'm probably blind, but could someone point me to any relevant writing about spell areas and creatures larger than medium? Spell areas typically involve a certain number of 5" squares, as per each individual spell description (burst, cone etc).

As a large creature is 4 squares, a spell may cover the whole creature, 75%, 50% or 25% - how much of a creature needs to be covered by a spell effect for it to be effected? All of it? Half? Any part of it?

Thanks in advance!

 

[Li Shenron]

I'm not sure but I think you need to cover one square at least (and I think the area templates in DMG are done with in mind that a square is covered if it is more than 50% within the area?).

Incidentally, if you need to cover all of them, would a Lightning Bolt ever affect a creature larger than medium? Even a burst spell probably wouldn't, as creature itself may "block" the burst from affecting it's other side...