Most of the spells that affect Targets instead of an Area, uses the following formulae to limit the "area" of the effect:
"one creature/level, no two of which can be more than X ft. apart"
In these spells, the caster must have line of sight and line of effect to every target, but there is no need of line of effect between each of the targets.
Though, there are spells which use the word "burst" to define the targets that are affected. I've found these ones:
Cloak of Chaos
Confusion
Holy Aura
Shatter
Shield of Law
Stone to Flesh
Unholy Aura
Wail of the Banshee
Let's take Confusion as an example:
"Targets all creatures in a 15-ft.-radius burst"
I've thought of three possibe interpretations:
1. Design error. It should be corrected to something like:
"Targets any number of creatures no two of which can be more than 30 ft. apart"
but in this case the caster could choose to leave some creatures (allies) out of the effect. It should be better to remove the Targets description and use the Area description instead. Ex:
"Area: Creatures in a 15 feet radius burst"
The spell "Calm Emotions" works this way.
2. The targets must have line of effect and line of sight to the caster, and line of effect to the center of the "area".
3. The caster must have line of effect and line of sight to every target. I would use "sphere" here:
"Targets all creatures in a 15-ft.-radius sphere"
Thoughts?
For Confusion, Shatter and Wail of the Banshee, I would go with #1 (they should be area spells, not targeted spells).
For Stone to Flesh, it doesn't mention a burst at all, so it's just a normal targeted spell.
For the rest, where you can pick and choose the targets, I'd go with #3.
#2 seems very odd to me.
For Stone to Flesh, it doesn't mention a burst at all, so it's just a normal targeted spell.
I don't know how that spell was included in the list. I suppose I didn't check very well the filter I did in my excel sheet.