I have a situation here:

From what we know if some effect influances more then one player the controler of the effect has to go first right? Like with the plot Summoning season, if I play it I have to reveal first what I have searched for.

So i guess it is same with Valar Morghulis - I have to kill my characters first so I have to save them first if I want. This is correct right? But do all characters leave play at the same time or do mine characters leave first and after that my opponent starts to save his? I guess that all together so only the order of saves matter...right?

I asked because I have heared that if my Rhearar Targaryen is killed by Valar it prevents from all the responces: (like save etc) you go automaticaly to the next round. Is this some exception or does killing mean that he is marked as dead (and thus moribund) and does not have to leave the play to be actualy "killed" to trigger his ability?

In this scenario Rhaegar's response triggers well after save responses do. This means that every single character can be saved before the round ends.

Rozy said:

Actually, this is not correct. Valar kills all characters, which means that when the it initiates, everything is slated to die at the same time. There is no conflict involved because there is nothing for anyone to choose. The person who controls the effect "going first" really only applies to choosing things for initiation. So in Game of Cyvasse, where all players have to kneel a single character with an intrigue icon, the person playing the effect has to indicate which character they will choose first, but all chosen characters are knelt at the same time. Since Valar kills everything without any sort of order, there nothing for you to "do first." You could technically indicate all of your characters, then have your opponent indicate all of their characters, but since they all move on to Step 2 at the same time, there isn't really any point.

And even if you did "kill all your characters first," you would not save them first. Saves are a completely different step that all the characters reach at the same time. Players would take turns playing save effects, starting with the First Player. If you are both saving, technically your saves would be alternating (you save one, he saves one, you save one, etc).

Rozy said:

As eloooooooi indicates, Rhaegar's "end the round" effect is a standard Response, not a save, and thus waits until Step 5. So he doesn't end the round until after every player has had the chance to play every save they want. In fact, since Step 5 is the standard Response opportunity for all applicable response triggers, it is entirely possible for people to play other Responses to those characters being killed, revealing the plot, etc. before a player actually triggers Rhaegar.

If this still doesn't make sense, I'll map out the action window tonight when I have more time.

No the chart is not necessary it is clear now. I think I got too much into the problem that was pretty easy. There is nothing to choose separetly and they all die together. Got it.

But I guess that with Wildfire I would have to choose my 3 standing characters first, then my opponent. But I could still use things like Icy Catapult to kill one of his surviving 3 characters since in the point when I could trigger the response I would already know what 3 had he chosen...

Rozy said:

Yes. That is how Wildfire would work. You'd have to indicate your 3 chosen to live, then your opponent. So your opponent has the added information of which 3 you are going to be keeping around before he/she has to make his choice. Then all characters not chosen are killed at the same time. By the time you get to Responses like Icy Catapult, not only do you know which 3 he chose to live, but all the others (for both of you) are dead (well, moribund, anyway).