when does a full round spell come into effect?

[claudekennilol]

Specifically when does enlarge happen? If I cast enlarge person as a full round, or summon monster, when does it come into effect?

[That Crazy Alchemist]

Enlarge is actually a "1 round" casting time rather than a "full round". Enlarge's effects will take place just before the initiative count of when you cast it.

[Nefreet]

Spells that take a full-round action to cast, such as spontaneous spells modified by metamagic, take effect immediately (the same round they are cast).

Spells with a casting time of 1 round take effect immediately next round.

[claudekennilol]

Ok, that's what I thought. Where in the book is that found so that next time this comes up I can reference it quickly?

[Nefreet]

In the Core Rulebook, in the Magic Chapter.

[Lifat]

Which means we have several different casting times:
1 immediate action (takes effect immediately... See what I did there? :P)
1 swift action (takes effect immediately)
1 standard action (takes effect immediately)
1 full round action (takes up all your turn except swift/immediate and free actions but takes effect immediately)
1 round action (takes up all your turn except swift/immediate and free actions but takes effect just before your next turn)

Longer cast times should take effect after the time has passed immediately before your next turn.