指的是dru6的fire seeds？为什么会拿这个打蝙蝠集群……anyway……fire seeds的描述里有Targets: Up to four touched acorns or up to eight touched holly berries
所以不是single targeted。这个法术target的是一框种子。然后你用种子丢人要按照每种用法分别讨论：
Acorn Grenades
As many as four acorns turn into special splash weapons that can be hurled as far as 100 feet.
这个应该没啥争议吧，不仅能打而且还能多打50%伤害
Holly Berry Bombs
You turn as many as eight holly berries into special bombs. The holly berries are usually placed by hand, since they are too light to make effective thrown weapons (they can be tossed only 5 feet). If you are within 200 feet and speak a word of command, each berry instantly bursts into flame, causing 1d8 points of fire damage +1 point per caster level to every creature in a 5-foot radius burst and igniting any combustible materials within 5 feet. A creature in the area that makes a successful Reflex saving throw takes only half damage.
明显是个aoe，也是50%额外伤害。以上
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从cr来看，我估计lz问的更可能是dru1的produce flame。这样的话：
首先法术描述中没有target，Effect写的是Flame in your palm。所以不存在单体目标的问题。
其次下面的描述文字里：You can strike an opponent with a melee touch attack, dealing fire damage equal to 1d6 +1 point per caster level (maximum +5). Alternatively, you can hurl the flames up to 120 feet as a thrown weapon. When doing so, you attack with a ranged touch attack (with no range penalty) and deal the same damage as with the melee attack.
扔火球的描述很清楚，相当于投掷武器，那么参见Vulnerabilities Of Swarms第二条：A weapon with a special ability such as flaming or frost deals its full energy damage with each hit, even if the weapon’s normal damage can’t affect the swarm. 很显然火球没有武器伤害只有special ability的伤害，所以造成全额伤害。
近战的描述没有说明攻击的方式，所以应该理解为需要接触攻击的法术(如电爪)，因此是属于swarm traits中所说的单体法术范围的。参见srd Swarm Subtype第四段“A swarm is immune to any spell or effect that targets a specific number of creatures (including single-target spells such as disintegrate)”。这里举了解离术的例子(我认为非常非常之糟糕，因为它扩大了single targeted spell的范围)，而解离术是个ray而不是Target: One creature，也就是说有攻击骰的法术只要没有说strike as a weapon就算作是单体攻击的法术。所以抠字眼的话用produce flame近战攻击swarm是要被免疫的。
以上都是纯核心的讨论。我好像有印象PHB2或者ca里的feat之前有一段spells as weapon，里面可能对这部分有修正。
