When do attacks of opportunity 'refresh'

Question

We have a PC in the party who can cause enemies to provoke on his turn. The question is, when does his pool (combat reflexes) of AOOs 'refresh'?

The rules, as far as I can tell, simply say 'one per round'.

Answer 1

I think RAI is that all character's AoOs will refresh at the start of each Round which means at the start of the highest initiative character's turn.

An attack of opportunity is a single melee attack, and most characters can only make one per round Attacks of Opportunity

Combat is measured in rounds. During an individual round, all creatures have a chance to take a turn to act, in order of initiative. A round represents 6 seconds in the game world. Round

(Emphasis mine)

Since it doesn't specify a particular point in the round(and doesn't specify at the start of a character's turn) this indicates that everyone gets a new pool of AoO's at the start of each new round(regardless of turn order) to be used anytime an enemy provokes during that round.

If it refreshed at the start of the characters turn then a round would have to be from each characters turn until their next turn, not from highest initiative to lowest initiative.

This makes sense because each Round is really everyone going at once in a 6 second period. Turns are only there for logical gameplay while really everything is happening at once. That's why your dexterity applies to Combat reflexes because your quick reflexes allow you to do more in that 6 second window.

Here's why it matters.

Initiative Order:

1. NPC1
2. PC1
3. NPC2

Round 1

NPC1 provokes and AoO from PC1. PC1 preforms the AoO.

PC1 acts normally on their turn.

NPC2 provokes but PC1 cannot perform since the AoO was used for this round on NPC1.

Round 2(All character's AoOs refresh)

NPC1 provokes(PC1 can make the AoO because it is a new round even though it hasn't been PC1s turn again)

PC1 acts normally

NPC2 provokes(PC1 CANNOT make the AoO because it was used this round when NPC1 provoked)

If you're not refreshing at the start of the round then PC1 would not get their AoO against NPC1 because they haven't gotten their turn in Round 2 and so their pool hasn't refreshed. PC 1 would only be able to make the AoO against NPC2 in Round 2.

May not matter but if that AoO would've killed NPC1 and instead NPC1 kills PC1, you've got a problem.

Answer 2

I can't put my finger on the exact rule (if it's even spelled out in the books) but my groups have always run it as actions refresh at the start of a characters turn each round, unless something specifically says otherwise.

In your case, your player has 1 (or more if he has Combat Reflexes) AoO that he can use anytime between the start of his current turn and the start of his next turn. At the start of his next turn he again has 1 (or more) AoO that he can use.

Answer 3

When your player turn arrives, he always have right to a new set of AoOs until his next turn.

There is no such thing as an AoO pool 'refresh'. After your initiative value comes in the next round, a full round has passed for you and any AoO performed during previous rounds does not count any longer to your AoO per round limit.

First, what is a round? From Common Terms:

Round: Combat is measured in rounds. During an individual round, all creatures have a chance to take a turn to act, in order of initiative. A round represents 6 seconds in the game world.

This is further clarified in the Combat rules when it comes to an individual character actions. The Combat round:

Each round represents 6 seconds in the game world; there are 10 rounds in a minute of combat. A round normally allows each character involved in a combat situation to act.

Each round's activity begins with the character with the highest initiative result and then proceeds in order. When a character's turn comes up in the initiative sequence, that character performs his entire round's worth of actions. (For exceptions, see Attacks of Opportunity and Special Initiative Actions.)

When the rules refer to a “full round”, they usually mean a span of time from a particular initiative count in one round to the same initiative count in the next round. Effects that last a certain number of rounds end just before the same initiative count that they began on.

So despite initiative, it seems the actions of all characters are happening at the same 6 seconds span. Initiative is just a way to order what happens before in that 6 seconds span, and when it comes to effects that last rounds the combat rules state they finish at the start of the same initiative count where they begun.

Thus just as a 1 round spell would take effect only until the beginning of the next turn of the creature that cast it, it seems natural that creature can perform new AoO once its new turn arrives because it has totally spend its previous round span.

First round and Combat Reflexes

Because you cannot take AoOs while you have not acted in a combat, there is usually no problem counting how many AoOs you can perform during first round.

Now, what happens when you can take AoOs before your first round of actions. For example when you have Combat Reflexes like the example in the original question. In my opinion, that means AoOs performed before you first act in combat count towards a previous initial round, so when your initiative comes at round 1, you have a full round of actions including a new set of AoOs.

This works more cohesively with the way immediate actions work, so when your turn comes, you are able to interrupt other's action with one immediate action until your turn in the next round arrives.