D&D 3E/3.5 Casting Defensivly - 3.5 rules

[Elocin]

Can someone point me in the right direction in the PHB about where it states the rules for Casting Defensively (CD). I remember reading somewhere the DC for CD would be against the attackers attack roll if they were in melee combat. Now when I read about CD in the PHB on pages 140 and 170 all it says that the dc for CD is 15+ the spell level. I ultimately HATE this rule as there is no way any caster would fail such a save as the highest DC would be 24 and what caster does not stick their full ranks in Concentration (besides for flavor reasons).

Can someone point me in the right direction? Might be too late for my Magister last night as an Ancient Blue Dragon dug a pit underneath me and I was so in his threat range it did not matter at all and I died a horrible death as I failed 3 of my CD checks, but that is another story. And not that I am typing this I might have read this little CD rule in Monte's AU book and am just getting the two mixed up. (My DM let me try out the Magister in his 3.5 game as I am running an AU campaign next and needed to try some things out to get more familiar with the system.

Anyway any help would be appreciated.

tia

 

[Li Shenron]

I remember reading somewhere the DC for CD would be against the attackers attack roll if they were in melee combat.

If you cast defensively, you don't provoke an AoO. There is no attack roll.

 

[Darklone]

Casting on the Defensive: Casting a spell while on the defensive does not provoke an attack of opportunity. It does, however, require a Concentration check (DC 15 + spell level) to pull off. Failure means that you lose the spell.

It's in the beginning of the combat chapter or Combat1 in the SRD.

 

[Quasqueton]

I ultimately HATE this rule as there is no way any caster would fail such a save as the highest DC would be 24 and what caster does not stick their full ranks in Concentration. . .

I died a horrible death as I failed 3 of my CD checks. . .

Interesting contradiction there.

Also interesting that I don't think I've seen any mage max out Concentration ranks -- they spend points on other skills. I have seen some clerics do that.

And at 15+spell level, a 1st-level caster would need +15 Concentration. How does a low-level caster get that? A 5th-level caster would need +17 -- that's 8 ranks, +4 for Combat Casting, but where does the other +5 come from? A 9th-level caster would need +19 -- that's 12 ranks, +4 for Combat Casting, but where does the other +3 come from? A mage with 16 Con? That's possible, but far from common.

I see so much hyperbole from people who dislike a particular rule, its hard to tell what they are really arguing.

Quasqueton

 

[Joshua Randall]

Quasqueton is right. Casting Defensively is not as easy as it seems.

Take a 1st level wizard or cleric with 14 Con and 4 ranks in Concentration, a total of +6. That means that to successfully cast a 1st level spell defensively, he needs to roll a 10 or better (10 + 6 = 16). That's a 55% chance of success, or looked at the other way, a 45% chance of failure.

Would you wear armor that had 45% spell failure? I didn't think so.

Casting defensively is an act of desperation in order to avoid an AOO. If you get to that point (especially as a standard fire-support wizard, rather than a melee'ing cleric), you're in big trouble.

 

[mikebr99]

A 9th-level caster would need +19 -- that's 12 ranks, +4 for Combat Casting, but where does the other +3 come from?
Quasqueton

Skill Focus - Concentration...


Mike

 

[rushlight]

The standard cast defensivly is just 15+spell - which is an awful mechanic once your players are past 9th level or so. I houseruled the DC to be the monster's normal to-hit + spell level.

So like a basic orc would add like +3 or 4 (for his BAB and STR) to the spell level - for a 10th level mage, that's nothing. But when facing that huge dragon that has a +47 to-hit... well, a 10th level mage shouldn't stand that close to a huge dragon.

It's also worked in the party's favor. Before, fighter-types would usually concentrate on the other melee creatures only, letting the spell casters duke it out - under the old rules, there's not much of a chance of a fighter being able to screw up a spell. Now, they have the power to prevent spellcasting, and keep the other spellcasters off balance just like what happens to them.

FWIW, I use a similar system for Tumble checks. It just doesn't make sense that you have the same chance of failure tumbling through a goblin's square as you do tumbling through that huge dragon's square.

 

[mikebr99]

The standard cast defensivly is just 15+spell - which is an awful mechanic once your players are past 9th level or so. I houseruled the DC to be the monster's normal to-hit + spell level.

So like a basic orc would add like +3 or 4 (for his BAB and STR) to the spell level - for a 10th level mage, that's nothing. But when facing that huge dragon that has a +47 to-hit... well, a 10th level mage shouldn't stand that close to a huge dragon.

It's also worked in the party's favor. Before, fighter-types would usually concentrate on the other melee creatures only, letting the spell casters duke it out - under the old rules, there's not much of a chance of a fighter being able to screw up a spell. Now, they have the power to prevent spellcasting, and keep the other spellcasters off balance just like what happens to them.

FWIW, I use a similar system for Tumble checks. It just doesn't make sense that you have the same chance of failure tumbling through a goblin's square as you do tumbling through that huge dragon's square.

I'd be leaning towards more of the Reflex save mechanic then the BAB... seems more in line that a quick person would be better at reacting to a caster then the hill giant... YMMV

Mike

 

[rushlight]

As for why 9th level is the point where casting defensively no longer really matters, here's the basis:


Skill ranks: +12
Con: +2 (or more, if you've got access to Create Wonderous Items. And who makes a wizard with a bad Con? You've only got a d4 for Hps!)
Casting Defensively: +4
Die roll: Avg of 10

That's a total of 28. So the max for a 9th level spell is 24 - you beat that on average more that 50% of the time. But you can only cast 5th level spells, so your max at 9th level will be DC 20. That means you only need to roll a 2. There's a 5% chance of failure. That's basically meaningless. Your max DC only goes up 1 for every 2 levels that you gain - but your skill rises at twice that rate, not to mention the possibility of stat increases.

Translation: The DC doesn't scale with the level of the encounters. I feel it should - so at least it does in my game!

 

[Darklone]

Hmm. Con build gnome illusionist 3.0. Level1, 4 ranks, con +5, toad +1, combat casting... no problem.