Counterspelling- Do I have this right?

[Garan]

Counterspelling goes as follows: On your turn, you ready an action to counterspell a targeted spellcaster's spell.
When this happens, you make a DC Spellcraft 15+spell level to identify it (you also make this check for anytime a spell is cast? Would it make sense to give a circumstance bonus to those who are aware of what is about to happen?).
You then expend the SAME spell (minus any metamagic feats either of the casters apply) to counterspell it. Certain spells also work against ones diametrically opposed as mentioned in their spell description. Improved counterspell makes any spell able to counter a spell in the same school that is lower than its spell level. Dispelling can also be used, but it requires a dispel check instead of a Spellcraft spell.

Important question though: Doesn't this mean that a non-spontaneous caster would have to have the spell they are trying to counter prepared already? It seems like spontaneous casters might be more versatile in this regard because as long as they know the spell and haven't used up all of their spells of that level for that day, they can counterspell, not to mention how Improved Counterspell helps them.
And wouldn't specialist wizards never be able to counter a spell from their forbidden school?

[dascarletm]

Looks right.

I built a counterspelling sorcerer for to mess with the party wizard. It was a sorcerer, she tried to get a spell of every school on her list per spell level. Dispel magic was for when she didn't have it.

[Diarmuid]

I think the more common approach you're going to see is people using Dispel Magic or Greater Dispel magic to counterspell as opposed to the same spell.

This is more flexible and doesnt require the spellcraft roll. Sure if you identify the spell and you happen to have the same one prepared it probably makes more sense to use that (leaving your Dispel for something else later) but more often than not you wont have the same spell available.

[Eiko]

You can also pimp your dispel checks fairly easily to beat appropriately leveled encounters. A pair of feats will let you autodispel everyone's spells who's CL is not 5 higher than yours, since you only have to tie with them to dispel.

Arcane mastery means you can take 10 on the dispel check, Planar touchstone (catalogues of enlightenment) gets you the power of the inquisition domain (+4 to dispel checks).

[Studoku]

You can also pimp your dispel checks fairly easily to beat appropriately leveled encounters. A pair of feats will let you autodispel everyone's spells who's CL is not 5 higher than yours, since you only have to tie with them to dispel.
What fests are these? They sound fun.

[ahenobarbi]

Arcane Mastery is from Complete Arcane, Planar Touchstone is from Manual of the Planes.

[hoverfrog]

Does this come up often? I have never had a player even think about counter spelling an enemy caster. Not even once.

[Diarmuid]

I wouldnt say it's a terribly common thing, but it has come up enough times in my games that I'm familiar with the rules.

I would say it probably doesnt really start becoming a viable tactic until around level 8-9 and mid to high teens would be when you'd be able to pull off some of the more advanced synergy (countering as free or immediate actions, etc).

[Seharvepernfan]

Counterspelling goes as follows: On your turn, you ready an action to counterspell a targeted spellcaster's spell.
When this happens, you make a DC Spellcraft 15+spell level to identify it (you also make this check for anytime a spell is cast? Would it make sense to give a circumstance bonus to those who are aware of what is about to happen?).
You then expend the SAME spell (minus any metamagic feats either of the casters apply) to counterspell it. Certain spells also work against ones diametrically opposed as mentioned in their spell description. Improved counterspell makes any spell able to counter a spell in the same school that is lower than its spell level. Dispelling can also be used, but it requires a dispel check instead of a Spellcraft spell.

Important question though: Doesn't this mean that a non-spontaneous caster would have to have the spell they are trying to counter prepared already? It seems like spontaneous casters might be more versatile in this regard because as long as they know the spell and haven't used up all of their spells of that level for that day, they can counterspell, not to mention how Improved Counterspell helps them.
And wouldn't specialist wizards never be able to counter a spell from their forbidden school?

All correct.

[Kelb_Panthera]

Arcane Mastery is from Complete Arcane, Planar Touchstone is from Planar Handbook.
FIFY.

Counterspelling is kind of a niche thing. It's only real use is to suppress the enemy caster's spells so you can take him alive.

You could accomplish the same task by readying an action to fire a damaging spell into his face with very solid reliability, and if you pick up non-lethal substitution instead of improved counterspell he'll still be alive afterwards but conciderably more docile, what with being out cold and all.

You do seem to have the rules down though, so kudos to you.

[eggs]

Does this come up often? I have never had a player even think about counter spelling an enemy caster. Not even once.
I do it a lot on Clerics and Shamans. Poking into someone's turn, looking at what they're trying to do and responding with "hahahahaNO" is awesome.

But without Divine Defiance/Battlemagic Perception, it's a bit less awesome.