My buddies and I were recently playing 3rd edition D&D. I have a 6 Level fighter / 5 Level Bard and I was getting attacked by a Necromancer. The necromaner had mirror image on him and I droped him down to 3 images left when we got the same init on the next round. I rolled my first attack and hit him, not the mirror image. Did 38 points of damage with my weapon, he cast a power word stun.
There are a few factors here.
Would he have to roll a concentration check for the spell since i hit him?
Would I get my second attack before the spells results?
So it ended with me just there laying on the floor of a ship while he ganks my stuff.... My Rod of flailing +3 with cold fire damage... GONE... 
I'm getting screwed!!
Any thoughts?
Thanks
Suppose a fighter and an archer go at the same
initiative....
The question is moot, because two characters never have
the same initiative. If two characters tie with their initiative
rolls, you must break the tie before starting the combat (see
Initiative in Chapter 8 of the PH)....
Hope this helps.
Two, if two combatants roll identical initiative numbers, there's a method to determine who goes first (can't recall the 3e version); there's no such thing as simultaneous initiative.
And this is why you never houserule so that simo-initiative happens. It sounds cool at first, but opens up a boat of issues.
-Sarena
Then I just go by placement at the table, saves a lot of time that way with less die rolling.
Allowing "simultaneous actions" affects nothing within the game itself and serves only to make playing the game more difficult and confusing. I can only assume any DM who allows it does so out of some misguided nod to "realism" without fully understanding its purpose and the consequences of changing it.
What about the Mirror image spell, would i know the real from the fake in this round, or would the DM have to roll for which one i hit for my second attack this round?
And asuming i went first in the round would he have to roll a concentration to keep his spell?
What about the Mirror image spell, would i know the real from the fake in this round, or would the DM have to roll for which one i hit for my second attack this round?
Once you've hit the real target, you know which one it is for at least the rest of your turn. Once the caster's turn begins, he/she must move to confuse observers and regain the benefits of the spell. From the PHB: "While moving, you can merge with and split off from figments so that enemies who have learned which image is real are again confounded." The rules are silent on exactly what "move" means. Some DM's allow a 5' step to qualify (I do), others insist that the caster must travel farther and use a move action. Ask your DM.
Also, the FAQ has a discussion of Mirror Image that you may want to read.
And asuming i went first in the round would he have to roll a concentration to keep his spell?
I'm pretty sure you can only disrupt a spell while it is being cast. If you get an AoO because the caster is casting in a threatened area, then you might disrupt the spell. Otherwise, you have to ready an action to do so. Damaging a caster in the same round, but before he casts the spell, doesn't disrupt.
Hope this helps
Edit: You might also consider posting future questions in one of the Previous Editions forum. It's perfectly okay to post 3.X questions here, but there tends to be more 4th Ed. people here, and more 3.X people there.