PF Question.. When do spells take effect?

[Blackfoot]

I got to thinking about this and now I'm wondering. There are many spells that have their duration in 'rounds/level' as such... at level 1 they only have a duration of 'one round'. Do these spells end BEFORE or AFTER your next turn? If the spell effect begins when you have completed your action.. then one might assume the spell began AFTER your turn... and therefore would end AFTER your next turn.
Spells like 'Daze' have this sort of issue... or (the one I was looking at when this came to mind) 'Bomber's Eye'. If the spell grants a bonus to throwing bombs.. but since drinking the extract is a standard action... when you go to throw the bomb on your next turn the spell has already worn off.. (assuming the spell ends (as the Combat Tracker does it) just before your turn)
What is the 'right way'?
Anyone know?

[JohnD]

Shouldn't something like that end after your next round, not before?

[Trenloe]

A bit of a discussion about it here on the Paizo messageboards: https://paizo.com/forums/dmtz38c4?Duration-of-One-Round#0

This refers you to P178 of the core rulebook or see the last sentence of "The Combat Round" section in the PRD: https://paizo.com/pathfinderRPG/prd/combat.html

Which states:
Effects that last a certain number of rounds end just before the same initiative count that they began on.
So, FG effects are working currectly. But, yes, it does nerf a few spells/extracts when CL1.

[Blackfoot]

The real question is 'when do they begin'. Certainly they don't begin until the end of the caster's action on the round that they are cast... hrm. So do they begin on the init count AFTER the caster cast his spell? That wouldn't be quite right either.. especially if the target had the same init count as the caster and just happened to go after him... or maybe that WOULD be right... if the caster and the target have the 'same' init count then target would be unaffected until just after it acted as well... hmm. Messy.

[lachancery]

The real question is 'when do they begin'. Certainly they don't begin until the end of the caster's action on the round that they are cast... hrm. So do they begin on the init count AFTER the caster cast his spell? That wouldn't be quite right either.. especially if the target had the same init count as the caster and just happened to go after him... or maybe that WOULD be right... if the caster and the target have the 'same' init count then target would be unaffected until just after it acted as well... hmm. Messy.
This question is ageless and is pertinent to most rulesystems. I was having a similar discussion with Dakadin about the timers in the combat tracker of the Rolemaster ruleset. Personally, I rule it as you describe above - in this case, I would make the spell "begin" after it is cast, thus it would still be in effect during the standard action of the next round.

[Crossfireue]

My group has typically always played that the spell pops after exactly 1 round, so it lasts through the caster's NEXT action (when, usually, the start of another spell would begin). This way the caster can enjoy the effects of a spell they cast the previous round.

Example; An enemy has initiative of 15, the caster 12. Round 1, the enemy swings a longsword and misses the caster. On init 12, caster throws Color Spray spell successfully, stunning the enemy for 1 round. On it's next turn, the enemy is Stunned and cannot act. On their turn, the caster throws a fireball, and the enemy still suffers from the -2 AC loss in addition to no bonus from Dexterity. On Init 11, the Color Spray effect pops and when combat comes back around to 15, the enemy (slightly toasted) is free to act normally.

Not saying this is the right way to do it, it's just what we do. It works this way for enemy casters as well.

[Gwaihir Scout]

I would houserule that 1 round buffs last through your next turn, so you can actually use them.

One round debuffs (like Stunning Fist, or Cause Fear if the target saves) follow RAW, so that your allies get the advantage, but you don't.

[Blackfoot]

It is a sticky one to be sure.
One could argue the RAW based on when the effect actually begins. Certainly spells that have no actual effect during the caster's 'round' seem 'broken'. Even in the case of spells that are supposed to last '5 rounds' but only last '4' of the caster's rounds don't seem quite right.

This becomes simpler with spells with a full round casting time. The effect begins at the start of your NEXT action and ends at the start of the caster's 3rd action.
A cleaner rule for the whole thing seems to be in order.

[Gwaihir Scout]

Well, the defensive buffs (including Vanish, despite rogues using it offensively) are fine as they are. Offensive buffs are usually applied to allies instead of the caster, so that's fine too. It's only an issue if your character intends to buff himself and then go fighting. Most combats only last a few rounds.

How many low-level offensive buffs are there that are measured in rounds/level, anyway?

[Blackfoot]

I'm not sure if it is 'fine' that they are... I don't see a reason for the caster to lose their round of effect.
... and in answer to your question, there are actually a lot of spells that work on a per round basis... especially the lower level ones. Take a look through the spell lists.
The following is a partial list of spells that are 'useless' at level 1:
(even though you can potentially take them as one of your few known spells and depending on the character/class type this can be very dramatic)
Sun Metal.
Adjuring Step.
Targeted Bomb Admixture.
Bomber's Eye.
Jury-Rig.
Borrow Skill. (unless the skill can be performed as a move action)

Limited usefulness to the caster:
Vanish - caster gets an invisible 'move action' but no standard.
Touch of Gracelessness - caster does not get an attack on the graceless target.
Glitterdust - caster does not get to make an attack against revealed targets.
Daze & Color Spray on targets over 5HD - Caster gets no benefit other other than a safe move action and delaying the combat for a round and wasting a spell. (assuming he doesn't have friends to smack the target)
Forced Quiet - kinda tricky with only 1 round... target readies an action to scream as soon as the spell lifts.. bard can move up to them but cannot strike until the same moment as the target gets to scream... ok the bard probably isn't taking him out anyway... questionable uselessness.
Divine Favor & Wrath - work for 9 rounds not 10.
Stalwart Resolve - useless on the caster except as it applies to move actions.
Tactical Acumen - only partially useful for the caster.
Ghostbane Dirge - useless for the caster.

These are OK because of 'special rules':
Feather Fall - works because the casting time is 'immediate'.
Animate Rope - only works if the rope action is assumed to be part of the casting.
True Strike - only works because it has special rules allowing it to function until the END of the caster's next action.
Command - is ok because the 'round' actually begins on the target's turn rather than the caster's.

Seems like what this boils down to is that personal offense buff spells tend to break under the rules unless there are specifics for handling the casting round built into them.