Why wouldn't you always cast on the defensive?

[ciaran00]

Could someone explain to me why casting on the defensive is an option at all? Why wouldn't you do it all the time? And if you would (while threatened) then you always have a constant % chance of failure that sucks at lower levels but is inconsequential at high ones.

Correct me if I'm wrong, which I probably am??

Thanks.
ciaran

 

[the Jester]

Well, you lose your spell if you fail your check. Of course, that's only likely at low levels- a 4th-level wizard could easily have +9-13 Concentration, and they're only gonna fail once in a while.

 

[Nifft]

As you mention, casting defensively means you might lose the spell. So, you're screwed.

A fighter at or above level 6 gets multiple attacks, so he might be able to kill the mage in about half the time if he didn't bother delaying.

Of course, a fighter could also just grapple the mage...

-- N

 

[clark411]

Concentration is already almost required to play a caster. A couple wizards who are either really confident in their ability to not get into melee may opt to not invest in the skill, as may a couple who either have no intentions of spelunking into dungeons. This would shunt the skill straight into "required" bin, and it seems that by and large, no skill should be *absolutely* required to play without messing up all the time.

It's really akin to putting in a "Swordplay" skill for fighters and requiring them to roll a check to not fumble around. Melee and ranged swings are negated by AC, Spells are negated by Saves and SR. Is introducing a third way for Spells to malfunction or negate the utility of low level wizards needed? Taking another tack, do Wizards have one too many skillpoints to choose from each level?

Now, if you're just asking why they don't always cast defensively without suggesting they should... I dunno, I think my wizard would feel absolutely horrible if, alone in his room with a mirror, he messed up casting Scry because he failed to cast defensively. Barring the fact that he kept the Monster under the bed from hitting him, and letting the Boogey Man in the closet know he's on to him.. it'd be completely silly. ^_^

 

[Elder-Basilisk]

You hit the nail on the head. The reason that you don't always cast defensively is that you might fail. A character with a skill check high enough not to fail might as well cast Scry of Rary's Mnemonic Enhancer while concentrating to keep his eyes on his surroundings. However, most wouldn't bother.

As to why it's a skill, there are a few things I noticed when playing some of the 1e abandonware gold box computer games. If damaged while casting a spell you always lost the spell. Whenever a foe began casting a spell it was always a good idea to hit him once--even if you had to use a multi-attack weapon like darts to do it. On the other hand, if you beat them in initiative (1e didn't have cyclical initiative) that round, you could cast a spell while surrounded by 9 orcs with falchions (or whisper spiders) and none of them would have a chance of messing you up.

In 3e, the concentration skill and casting defensively helps solve both of those problems from prior editions. Concentration provides a way to have a chance at keeping your spell if you're damaged while casting. It also (combined with AoOs) gives the 9 orcs a way to keep you from casting your spell (especially since the cyclical initiative means that the 1e "if you've already been damaged this round, you can't cast a spell" can't work). I think it serves both of those functions quite well.

As to the rest, I think it's good that it's a skill just like it's good that spell focus is a feat. Nearly every spellcaster will want concentration but every spellcaster won't. A wizard (or more likely a sorceror--let's fac it, wizards usually have enough skill points to spend them on concentration) who counts on staying out of combat and has another use for the skill points might not max concentration. Most wizards will. As will most clerics. On the other hand, multiclassed clerics and wizards who don't view spellcasting as their primary combat contribution might not bother to put any points in concentration. I don't spend many points in it when I play a paladin. Nor does my halfling fighter/cleric have any ranks in concentration. If she can't cast spells, that's no big deal; she won't have second level spells till 12th level anyway so they're not a really big part of her contribution to the party. She tries to cast her spells either before combat or after it. It hurts when she tries to cast CLW while her riding dog is double moving but she'd still rather have the knowledge religion ranks that will let her into the Templar class.

 

[Al'Kelhar]

I use a house rule which I've found very convenient and well-balanced.

Any spellcaster who chooses to cast a spell while threatened is automatically assumed to be casting on the defensive. However, the Concentration check is not a check to cast the spell while avoiding attacks of opportunity, it is an opposed roll against the attacker's attack roll. If the Concentration check is equal to or higher than the attacker's attack roll, the spellcaster succeeds in avoiding the attack and casts the spell. If the attack roll is higher than the Concentration check, the attacker hits the caster, doing damage and forcing the spellcaster to make another Concentration check at 10 + damage suffered + spell level to avoid losing the spell.

I find opposed rolls where there are opposed actions (e.g. casting spell vs AoA, tumble vs AoA) to be better balanced than fixed DCs, which are dead certainties for high level characters even when faced with equally formidable opponents. Thus, it's easy to cast a baleful polymorph on the bad-ass fighter standing at the back of the cave when surrounded by his orc henchmen, but quite risky to cast baleful polymorph on the bad-ass fighter standing next to you.

Cheers, Al'Kelhar

 

[Ripper-nk]

I use a house rule which I've found very convenient and well-balanced.

Any spellcaster who chooses to cast a spell while threatened is automatically assumed to be casting on the defensive. However, the Concentration check is not a check to cast the spell while avoiding attacks of opportunity, it is an opposed roll against the attacker's attack roll. If the Concentration check is equal to or higher than the attacker's attack roll, the spellcaster succeeds in avoiding the attack and casts the spell. If the attack roll is higher than the Concentration check, the attacker hits the caster, doing damage and forcing the spellcaster to make another Concentration check at 10 + damage suffered + spell level to avoid losing the spell.

Cheers, Al'Kelhar

In my opinion some actions are automatic when you real learn how to do.
the mage with +18 in concentration simply know how to cast a spell 3 circle or lower without open the guard.

 

[Elder-Basilisk]

I generally agree with Ripper on this. If you spend sixteen ranks in a skill you should get something good out of it and I have no problem with it being automatic. After all, the concentration check isn't actually to avoid any specific attack, instead it's for the character to retain his focus on casting the spell while not leaving an opening in his defenses. It doesn't seem like it would be any more difficult to concentrate on a spell while keeping your eyes on an orc than to concentrate on it while keeping your eyes on an ogre. In either case, the question is if you can concentrate on the spell while your eyes are elsewhere. That seems like exactly the kind of thing that a fixed DC is good for.

 

[fba827]

don't forget, that even though it is a fixed DC, there may be circumstances that the DM deems important enough to put on circumstance penalties to your skill check. While it is a rare case when that happens, depending on your DM and the situations at play, even if your skill modifier is higher than the fixed DC, you may still fail if there are situational penalties.

 

[pawsplay]

The Miniatures Handbook has that damned bee which should make any caster think twice about going light on ranks in Concentration.

Anyway, to answer the question: when you have the room and safety to take a 5 foot step and cast.