Residual magic wording.

[ayvango]

Lingering metamagic tactics has wording
" If you cast a spell affected by one or more metamagic feats, and then cast the same spell in the next round, you can apply any one of the metamagic effects from the first casting to the second casting, but without any change to the spell's level".

Normally you casts one spell per round, but there are means to cast more. So I'm wonder how this feat works in such conditions. Either it works on any two subsequent casting even if they occurred in the same round, or it requires specifically a round run between casts. In the latter case would ALL spells casts in the second round benefit from metamagic enhancement from the first round?

[MisterKaws]

Lingering metamagic tactics has wording
" If you cast a spell affected by one or more metamagic feats, and then cast the same spell in the next round, you can apply any one of the metamagic effects from the first casting to the second casting, but without any change to the spell's level".

Normally you casts one spell per round, but there are means to cast more. So I'm wonder how this feat works in such conditions. Either it works on any two subsequent casting even if they occurred in the same round, or it requires specifically a round run between casts. In the latter case would ALL spells casts in the second round benefit from metamagic enhancement from the first round?

By RAW, it works as mentioned in the second reading, so you could get pretty silly with Twin Greater Arcane Fusions if you put enough modifiers to them.

[Mr Adventurer]

No, it only applies to the second casting, in the next round.

[ExLibrisMortis]

By RAW, it works as mentioned in the second reading, so you could get pretty silly with Twin Greater Arcane Fusions if you put enough modifiers to them.
I agree with this.

[ayvango]

By RAW, it works as mentioned in the second reading, so you could get pretty silly with Twin Greater Arcane Fusions if you put enough modifiers to them.
Arcane Fusions usage could give a weird results. That is the direct consequence of dual spell level/slot level conception. If you read original wording, only spell level is what matters, so you could use Arcane Fusion to power twin maximized empowered chain Orb of Force. So the wording was "fixed" in errata.

But the fix open path to other abuses. Old abuses relied on situations where spell level < slot level. So wording changes to take slot level in account. But situation when slot level < spell level is also possible, and you release power of fusion's absurdness on such occasions.

Shadowcraft mage could be a good example. On the first round he uses metamagic buster to cast heightened to 10th level silent image from the 1st level slot. Divine metamagic, Bardic music metamagic, Incantatrix's instant metamagic, whatever else. He could use his 9th level spell how he wishes. Then in the second round dark magic descends upon mortals. The shadowcraft mage uses first level slot containing Silent Image to shape shadow into the miracle spell. Use miracle spell to mimic 5th level spell Arcane Fusion. Now he could cast two silent illusions each heightened above 9th level. So he could use first one to produce some side-effect and the second one to drive loop further. So the mage could cast infinite amount of spells per round.

The old versions was safer despite granting free metamagic to caster.

[Segev]

Just affirming: it works on a spell cast in the next round, by the RAW. The wording "on this second spell" refers to the counting as given in the feat. "You cast one spell, then another in the next round," the 'second' spell is the one in the next round, because it's the second one mentioned in the antecedent sentence. It doesn't matter if you also cast 12 other spells in the round you cast the "first" spell; the "second spell" referred to is the same spell being cast again in the next round, because "second" is counting the spells as mentioned in the sentence, not the spell(s) you're casting overall.

[Mr Adventurer]

Just affirming: it works on a spell cast in the next round, by the RAW. The wording "on this second spell" refers to the counting as given in the feat. "You cast one spell, then another in the next round," the 'second' spell is the one in the next round, because it's the second one mentioned in the antecedent sentence. It doesn't matter if you also cast 12 other spells in the round you cast the "first" spell; the "second spell" referred to is the same spell being cast again in the next round, because "second" is counting the spells as mentioned in the sentence, not the spell(s) you're casting overall.

I disagree with your analysis, but even accepting it, I agree with what you say in terms of "a spell" cast on the next round - not as many as you like.

[ayvango]

Just affirming: it works on a spell cast in the next round, by the RAW. The wording "on this second spell" refers to the counting as given in the feat. "You cast one spell, then another in the next round," the 'second' spell is the one in the next round, because it's the second one mentioned in the antecedent sentence. It doesn't matter if you also cast 12 other spells in the round you cast the "first" spell; the "second spell" referred to is the same spell being cast again in the next round, because "second" is counting the spells as mentioned in the sentence, not the spell(s) you're casting overall.
Spell application order is not what counted by the "second" spell. Use full wordings "If you cast a spell affected by one or more metamagic feats, and then cast the same spell in the next round". "second" is not the order of spell casting, the word relies to order of if-clause. If-clause depicts situation when two spells are cast. There first spell is defined by "using metamagic", the second spell by "being the same spell as first". So the feat works on any pair of such spells that meets the condition. There is no specific requirements for being exclusively cast spells.

So each time you cast spell check if the condition is fulfilled. Cast first spell in second round. Check condition, it's ok, use feat. Cast second spell in the same round, check condition, use feat, cast third spell, check condition, use feat and so on.

[Segev]

Spell application order is not what counted by the "second" spell. Use full wordings "If you cast a spell affected by one or more metamagic feats, and then cast the same spell in the next round". "second" is not the order of spell casting, the word relies to order of if-clause. If-clause depicts situation when two spells are cast. There first spell is defined by "using metamagic", the second spell by "being the same spell as first". So the feat works on any pair of such spells that meets the condition. There is no specific requirements for being exclusively cast spells.

So each time you cast spell check if the condition is fulfilled. Cast first spell in second round. Check condition, it's ok, use feat. Cast second spell in the same round, check condition, use feat, cast third spell, check condition, use feat and so on.

I think we're in agreement, and you just misparsed what I was saying, since you more or less repeated it in different words (assuming I'm parsing you correctly).

[ayvango]

I think we're in agreement, and you just misparsed what I was saying
That was me who misparsed your previous message.

My point is the feat gives many-to-many relation. If any pair of spells matches the if clause, the feat works. If you cast three different spells in the first round and the same spells in the second round then all second round spells get amplified. If you cast one of this spells three times, it would still be amplified three times.

[ExLibrisMortis]

My point is the feat gives many-to-many relation. If any pair of spells matches the if clause, the feat works. If you cast three different spells in the first round and the same spells in the second round then all second round spells get amplified. If you cast one of this spells three times, it would still be amplified three times.
This is also how I read it, for what it's worth.