Caliban said:
I never said you couldn't. Fire Shield has a visible effect, so would be able to target it individually.
I was referring to when you wrote:
“If you can discern the spell for some reason (because it has a visual effect and you made your spellcraft roll, or because you used detect magic for 3 rounds and made your spellcraft check), then you can target it normally.”
Here, you indicated that you needed a spellcraft roll for a visual effect spell. But, it seems like we are in sync on visual spells now.
Caliban said:
Spells like mage armor, shield, charm person, or dominate person do not have a visible effect, and thus would not be able to be targeted unless you had some method of perceiving them. If the DM is generous, see invisible might allow you to perceive a mage armor or shield spell directly, while for charm or dominate I think you would need detect magic (to see the magical aura's on the creature), and a spellcraft check (to determine which magical aura is the one you want to dispel).
I can understand this. I wouldn’t be this restrictive though depending on the situation.
I use Detect Magic and notice an abjuration spell and an illusion spell. I do not think a spellcraft roll should be required to dispel the abjuration spell unless there are multiple abjuration spells of the same power.
Caliban said:
To me, being able to perceive the target of your spell (when casting a targeted spell) is an absolute requirement, whether that target is a creature, object, or another spell.
I can understand this position as well. The reason I am not quite so in sync with this is that there are other spells that do not require that you see your target (ray spells for example) and dispel magic itself has other applications where you do not need to see a target (counterspelling, area dispels, etc.).
Hence, I view dispel magic as the ability to unlock pieces of magic as long as you basically know where they are.
So, if I know that Barney has a Doom spell cast on him because I made a spellcraft roll when it was cast and I know where Barney is, I basically know as much or more information about the spell than if I just see a Fire Shield where I might know nothing at all about the spell. It would seem that you should be able to dispel an invisible spell that you know exists in a given location easier than a visible one where you know nothing about the spell. Counterspelling allows you to dispel a spell before it even starts, even though you cannot see what you are counterspelling. Area dispels allow you to dispel an entire boatload of spells that you cannot perceive.
To me, these are a precedence for how single spell dispel should work. If you know where a spell is and what it is, you can dispel it. It’s fine that we disagree on this point.
Caliban said:
Sorry, but not in any game I run. It doesn't matter if you know exactly where an invisible person is, you still can't target them with a magic missile spell unless you can directly percieve them yourself.
Appropriately so since that is the rule on targeting a creature.
Caliban said:
The same would hold true for using dispel magic on a spell that you know is there, but cannot detect. You can't target it, although you could target the creature the spell is affecting, or use an area affect dispel.
Except that there is no rule for targeting a spell, hence, extrapolating the targeting a creature rule to a targeting a spell rule is fine, but not required.
In fact, I have a little bit of an issue with a missile can hit an invisible creature and a ray spell can hit an invisible creature, but even if I know exactly where an invisible creature is located, I cannot cast a spell on it, even by making a concealment roll. But, that’s the rule so I live with it. But, I will not use that same somewhat inferior (IMO) rule for dispels since dispels by their very nature are used to counter and dispel spells that cannot be seen. YMMV.