Blocking Spells

[Gurpser]

Okay, I agree that Blocking Spells suffer from the -1
per hax range penalty.

Can a spellcaster cast a blocking spell on the same turn
she casts a regular spell for example:


Start of Turn Sequence
The wizard casts a 1 second spell
the orc swings at the fighter
the goblin shoots at the wizard
the fighter swings at the orc
End of Turn Sequence

Can the wizard cast Deflect Missile to defend against the goblin's
arrow?

[Fred Brackin]

Originally Posted by Gurpser

Okay, I agree that Blocking Spells suffer from the -1
per hax range penalty.

Can a spellcaster cast a blocking spell on the same turn
she casts a regular spell for example:


Start of Turn Sequence
The wizard casts a 1 second spell
the orc swings at the fighter
the goblin shoots at the wizard
the fighter swings at the orc
End of Turn Sequence

Can the wizard cast Deflect Missile to defend against the goblin's
arrow?

Sure, business as usual. Deflect Missile specifically says the subject doesn't have to be the caster and mentions the Regular distance penalty. This is what the spell is for.

[munin]

Okay, Kromm says Blocking spells take Regular distance penalties (he talks about Mind Control spells specifically because I used the Command spell as an example in my question):

Originally Posted by Kromm

In most cases, Blocking spells work as the attack reaches you. They stop a spell or a weapon at range zero, and that's all they can do . . . you can't cast them at a distance. The rare few Mind Control spells that are Blocking by virtue of putting some sort of compulsion on the attacker work at no penalty as the attacker enters close combat, but otherwise take the -1/yard of Regular spells. The same goes for the few Blocking spells that can specifically be used to protect somebody else.

He didn't give a reference so I'm not sure yet if this is RAW somewhere or simply a Kromm ruling. *rules lawyer sadness*

[Dinadon]

Originally Posted by Gurpser

Okay, I agree that Blocking Spells suffer from the -1
per hax range penalty.

Can a spellcaster cast a blocking spell on the same turn
she casts a regular spell for example:


Start of Turn Sequence
The wizard casts a 1 second spell
the orc swings at the fighter
the goblin shoots at the wizard
the fighter swings at the orc
End of Turn Sequence

Can the wizard cast Deflect Missile to defend against the goblin's
arrow?

There is no 'turn sequence' in GURPS, just turns. Thus it is more accurate to describe it like this:

Wizard's turn: Cast's a 1 second spell
Orc's turn: Swings at Fighter
Goblin's turn: Shoots at Wizard
Fighter's turn: Swings at Orc.

From here you can see that it isn't the wizard's turn when the goblin attacks him. It wouldn't be the wizard's turn if the orc attacked him. The wizard's turn is over once he has resolved casting the spell. Of course, as mentioned here in the FAQ not everything in the rules uses that definition of turn length. These are the Active Defenses and things like them. Their use of the word turn applies until you start a new turn, that is:

Wizard's turn ---------------------------------->|Wizard's turn ------------
----------->|Goblin's turn ----------------------------------->|Goblin's turn
------------------------>|Orc's turn --------------------------------------
---------------------------------->|Fighter's turn -------------------------

Represents what's happening mechanically. Admittedly I just translate any mention of same or per turn in Active Defense rules into 'until you start a new turn'. Means I never have to use the second diagram.

Now to answer your question, yes. Only Blocking spells will prevent the casting of other spells. Casting 1 second spells will only prevent you casting a Blocking spell if you've used up all your energy sources, such as FP.

[Gurpser]

But the wizard in the above example could not cast a blocking spell vs. the goblin attack against him and the orc's attack against the fighter, correct?

[Dinadon]

Originally Posted by Gurpser

But the wizard in the above example could not cast a blocking spell vs. the goblin attack against him and the orc's attack against the fighter, correct?

Yep. Though there are options available in Thaumatology: Magical Styles that could let the wizard do so.

[vitruvian]

Originally Posted by Gurpser

But the wizard in the above example could not cast a blocking spell vs. the goblin attack against him and the orc's attack against the fighter, correct?

He certainly could use a blocking spell against the goblin's attack, unless the wizard's action on his own turn was (instead of a 1-second spell) something like All-Out Attack that disallowed active defenses. He should also be able to use it to benefit the fighter. However, if you meant can he do both, no, he could not, unless maybe he had Compartmentalized Mind and the spell at a high enough level he didn't need any ritual to cast, and the GM was nice and ruled that each compartment also counts for purposes of spell-based active defenses.