Same initiative roll

[ghostnote]

Hello,
I'm writing here because of a doubt that came up during the last game concerning opponents with the same Initiative roll. Here what happened in detail:
Bard from my party was in combat with a Babau demon. At the start of the fight they both rolled the same Initiative, but the Bard had higher Initiative modifier. They were in adjacent squares. So the bard started first (because of the higher modifier) and took a 5 foot step back to cast Cacophonous Call. The demon failed the saving throw and should have been affected by the spell. However, our GM decided that the demon should fulfill his attack since they had the same Initiative and were acting in the same time fraction of the round. Long story short, the demon hits the Bard, but after that is affected by the spell.
So my question is, is this the correct intepretation of the rule or the demon shouldn't have attacked at all, since it was affected already by the spell? When two opponents with the same Initiative are fighting, should there always be someone acting first or should they act in contemporary?
Thank you all in advance.

[DM_Blake]

Both viewpoints are correct, but the rules only support one: each combatant takes his full turn BEFORE the next combatant does anything, and anything the first combatant does will take effect and be fully applied before the second combatant gets his turn.

That's the RAW. AoOs and Readied Actions can interrupt the flow, but otherwise, it's one turn after the other.

Sure, the GM's point is valid. Turns are just abstract rules to allow us to run combats but the actual combats are dynamically happening all at the same time. But the RAW doesn't support this interpretation. It's true, but the rules just don't work this way.

If the bard had killed the babau, would the babau still get an attack? If his answer is yes, then does he do that for all combats? Everyone who begins a round gets to take their turn even if they're killed earlier in the round?

[Endency]

The demon should of been nauseated and unable to attack.

[Imbicatus]

The GM was not following the rules. If you have the same initiative roll, then the person withe the higher modifier goes first. Then the turns are in order. Period. The game does not support simultaneous actions without the use of immediate interrupt actions and readied actions, and even those happen in order.

In fact, the demon would have been flatfooted on your turn.

This is not supported by anything in the rules except rule 0.

[Lord Wimpy]

Having two characters take their turns at the same time is complete house rule territory. That being said, if the babau demon was holding it's longspear or another reach weapon at the time initiative was rolled (as opposed to needing to use a move action to equip it due to the weapon being sheathed), it would get an attack of opportunity on the bard for casting a spell, as babau demons have Combat Reflexes, allowing them to make AoO's while flat-footed.