There's been a lot of talk and confusion about how the targets of haste work. Here's how I see it: "one creature/level, no two of which can be more than
30 ft. apart" sounds like you pick your initial target (A) and the next target (B) has to be within 30 feet. From that target (B), the next target (C) has to be within 30 feet and so on. Otherwise, why wouldn't it say "choose one target/level within 30 feet," keeping in mind it still has close range, which would essentially be a burst. On that note, chain lightning specifically says "one primary target, plus one secondary target/level (each
of which must be within 30 ft. of the primary target)," although the picture in the core rulebook doesn't represent that too well :P... That sounds a lot more like a 30 foot burst than haste/slow. Would like to read some of your thoughts on this.
The way the spell works is no two targets can be more than 30 feet apart.
The reason it does not say "choose one target/level within 30 feet," is because that would mean the targets all had to be within 30 feet of the caster.
The it is written is that the greatest distance between any two targets is 30 feet.
As an example if the caster has a target 15 feet to his left, and another target 30 feet to his right one of them will not benefit from the spell because they are not within 30 feet of each other.
Can you find two targets that are more than 30ft apart? Well then... you've violated the condition that says "no two can be more than 30ft apart".
The reason it does not say "choose one target/level within 30 feet," is because that would mean the targets all had to be within 30 feet of the caster.
Remember, it still has a range to it, so it doesnt have to be within 30ft of the caster. Essentially it's sounding like the area of effect is like a 30 foot fireball instead of a line segment that bounces from target to target with the second target being within 30ft of the first, then the third target being within 30ft of the second, and so on.
"no two of which can be more than 30 ft. apart" means just that. It does not mean each additional target must be within 30' of the previous target. It means ALL targets must be within 30' of each other. In other words the spell effectively has a 15' radius burst centered on any point in space (you don't have to center it on a specific person to be effected).
Chain lightning has a primary target (not an arbitrary point in space as the center of the spell). From that primary target you then effectively have a 30' radius burst as all additional targets must be within 30' of the primary (but not necessarily within 30' of each other).
So I ran across another thing. Break Enchantment clearly states "up to one creature per level, all within 30 ft. of each other," p.251 in the core rulebook. Wouldn't haste/slow and others be worded this way if they were meant to be restrained to a 30ft. 'bubble'?
Pathfinder is not a legal document. Sometimes they use different words to mean the same thing. It was probably an artifact of several different designers and/or inherited from a previous edition.