关于强酸箭的问题仔细爬了一下老外的楼，老外也同表示压力很大
最后得到的疑似sage的答案如下：
As currently written, I'd allow the effects to stack. (Melf's) Acid Arrow has the line "Effect: One arrow of acid". Two such spells create two arrows of acid, and each arrow deals 2d4 points of damage. As a comparison, consider the spell (Mordenkainen's) Faithful Hound. It has the line "Effect: Phantom watchdog". If a wizard were to cast two such spells, would you argue that only one could attack any particular target each round?
Now, if Acid Arrow had a "Target:" line, then I'd agree that the effects would not stack, and the spellcaster would roll twice and take the better result. A spell of this nature would be Heat Meat, with the line "Target: Metal equipment of one creature per two levels, ..."
Now, cloud, fog and wall spells usually have an "Effect:" line as well, so by the same argument, I would allow the effects to stack. However, spells that have an "Area:" line instead would not, such as (Evard's) Black Tentacles.
This is based on my interpretation of the design considerations behind why some spells have an "Effect:" line and others have a "Target:" or "Area:" line.
简单的说，只有effect而没有area/target的法术叠，有area/target的法术取高
不是因为伤害都叠加，而是法术是否取同一对象造成效果
