Full round casting and concentration

[Alpha Polaris]

One of the players in the campaign I'm DMing is putting me in a delicate situation. The character, a monk/sorcerer going for abjurant champion, is in contact with several low-level threats. He decides to push the envelope, since some of his team mates need assistance, so he sidesteps and casts Enlarge person on himself.

Now enlarge person is a full-round spell, so the effects won't be effective until the start of his next turn. Now, I'm trying to understand what could happen in the meantime. First, does the player character threaten the area around him while casting ? If an opponent tries to grapple him to end the spell, can he take an AoO ? Does he lose his concentration for doing so ? Can he resist the grapple check normally ? Concentration ?

If an opponent (or several) instead make(s) several attacks (like 2 claws + bite), does he make a Concentration check for each attack that hits, just one with the highest DC, or a big one with a DC 11 + sum of damage dealt during the round ?

 

[Hypersmurf]

First, does the player character threaten the area around him while casting ? If an opponent tries to grapple him to end the spell, can he take an AoO ? Does he lose his concentration for doing so ?

He does not threaten, so he cannot take an AoO, so the question about concentration is irrelevant:

Cast a Spell
A spell that takes 1 round to cast is a full-round action. It comes into effect just before the beginning of your turn in the round after you began casting the spell. You then act normally after the spell is completed.

A spell that takes 1 minute to cast comes into effect just before your turn 1 minute later (and for each of those 10 rounds, you are casting a spell as a full-round action). These actions must be consecutive and uninterrupted, or the spell automatically fails.

When you begin a spell that takes 1 round or longer to cast, you must continue the invocations, gestures, and concentration from one round to just before your turn in the next round (at least). If you lose concentration after starting the spell and before it is complete, you lose the spell.

You only provoke attacks of opportunity when you begin casting a spell, even though you might continue casting for at least one full round. While casting a spell, you don't threaten any squares around you.

This action is otherwise identical to the cast a spell action described under Standard Actions.

Can he resist the grapple check normally ? Concentration ?

If an opponent (or several) instead make(s) several attacks (like 2 claws + bite), does he make a Concentration check for each attack that hits, just one with the highest DC, or a big one with a DC 11 + sum of damage dealt during the round ?

If the grapple is successful and the spell has Somatic components, the casting will automatically fail; you cannot cast a spell with S components in a grapple. If the touch attack succeeds but the caster successfully opposes the grapple check, I'd be inclined to call for the DC 10 "Vigorous Motion" check, but that's a judgement call, not an explicit rule.

Regarding multiple sources of damage - it's not a hundred percent clear whether 'damaged during the action' means 'you are damaged during the action', or 'you were damaged during the action'. But the latter leads to some counterintuitive results - it would mean that you could be attacked six times during the round, and you would not roll your Concentration check until just before the spell is due to come into effect... at which point you might roll so low that the first attack by itself would have been enough to disrupt the spell.

Since this seems awkward and inelegant, I'm inclined to take the other reading - if you are damaged at any time during the action, each source of damage forces a separate Concentration check with the DC determined by that source of damage, rather than a single check amalgamating the damage.

It means that Manyshot, for example, might force three easy checks rather than one difficult check, as each of the three arrows would be a separate source of damage (as shown by the interaction with DR).

-Hyp.

 

[Festivus]

Since this seems awkward and inelegant, I'm inclined to take the other reading - if you are damaged at any time during the action, each source of damage forces a separate Concentration check with the DC determined by that source of damage, rather than a single check amalgamating the damage.

It means that Manyshot, for example, might force three easy checks rather than one difficult check, as each of the three arrows would be a separate source of damage (as shown by the interaction with DR).

This hasn't come up for me yet, but I am also inclined with this interpretation as being what was intended, and is probably how I would rule it.

Thanks for sharing this, I love trolling this forum to educate myself