A lot of my post deals with NPCs vs PCs because my experience rarely involves PC characters going after each other outside of 1v1 or maybe 1v2 2v3ness.
1. Ideally if you have a large group of people, you would OOCly establish a posting order only to deviate from it when OOCly agreed (aka someone being attacked and player b dives to take the hit instead of player a)
The posting order generally is based on the situation. If it is an ambush... the ambushers etc. Generally, it is a good idea for the "GM" if against NPCS to get the first go just to set things up.
2. In larger groups vs smaller groups, I tend to have the larger groups not go any more than the smaller groups but have them do MORE STUFF on their turn so to speak. This is mostly so the PCs get to post often as well. As a GM you tend to need to post a lot, and sometimes it is best to dial down the detail a touch to get more things happening, and have more things happen per post so you aren't posting 3-4 times per PC post.
That may be difficult to do if the PCs are fighting in separate areas or against their own personal foe.
In Player vs Player, it is only fair everyone gets a posting turn unless otherwise discussed OOCly.
3. "Powerlevel" has a couple different ways to approach depending on the foes. When GMing Pathfinder or something, if the creature itself doesn't have an attack 'style' I will apply a personality to it.
Vulture: Goes after the weak (meaning low power level/injured people will get focused on and likely need help.)
Prideful: Goes after the strong as sense of pride of beating the big guy and not wanting to be seen as weak.
Guardian: Generally, goes after whoever is attacking one of its allies. This often will go after the leader as well.
Coward: Cheap shot guy, so once again may go after weak person.
Tactician: This one is more reading the battlefield and going after what seems the smartest at the time. (I avoid this one except for bosses and such because I don't want to "compete" against my players as the GM.)
(there are more I use but that is a sample.)
In general RP... this question flows quickly into 4.
4. If I am the one assigning the bad guys to fight certain people, I go for the way I think the players will enjoy the most. It may be being led by me, but it needs to have something for everyone, or at least something folks will enjoy. However, after I have 'assigned' in my own head who is going for who if the players change how I expected them to behave I roll with it... This could mean chaotic or more 1v1ish. A lot of times with mass combat if you are RPing the "fodder" I don't.... really treat the fodder with much concern. I let them be fodder and fall quickly... save for a few stronger ones.
5. Friendly fire... really is up to the people doing it. Sometimes a bad guy will sacrifice some lesser to get a good hit on a foe. As for player characters a lot of RP I have seen ends up with the line. "With friends like these who needs enemies."
6. Mass combat need patience from all parties. When you have fights with more than 3-4 people time between posting can get quite long. (The record I had was 1 hour... I cried) The "GM" often has to forgo detail and let the players have the fun with that until the combat thins out of the strong remaining. Often a solution is to have folks split off so they can continue their fights without having to wait for player B to post. (the 1v"1").
One RP I did I split the party into individuals at had their own enemies. It meant I was doing three times as many posts and my posts weren't as detailed as they could be, but it allowed the RP to keep a good pace and allowed each player to have as detailed posts as the wanted for their character. Then when they were brought together again, the combat style turned to 'fodder' where the 'scene' was set and then the players could include their kills in their posts so no one was waiting the GM between posts. Finally, it returned to a more organized posting order with the GM when the enemies were reduced to the strong and it needed a stronger guided hand.
Mass combat is very tricky due to the fact everyone has different styles of writing, different pace settings, and limited amount of patience. The other problem is we have fights that last an hour that in real time are 30 seconds if the detail is too great. In most films we see the protagonists in a mass battle and most everything around them is too chaotic to follow and people die left and right with little more than a stab, but then when they encounter a large strong foe the details of the fight get fleshed out and rest of the battlefield becomes a backdrop.
If we have all PC characters at once... you have too many "protagonists" for a cohesive and well paced battle if they are all together. Everyone wants lots of details... and the devil likes those.
Honestly... a "MASS BATTLE" between PC characters seems nigh impossible without splitting it into smaller chunks isolated from each other without running into mental limitations of players.
EDIT: As I find poor word choice this post may change.
1. Ideally if you have a large group of people, you would OOCly establish a posting order only to deviate from it when OOCly agreed (aka someone being attacked and player b dives to take the hit instead of player a)
The posting order generally is based on the situation. If it is an ambush... the ambushers etc. Generally, it is a good idea for the "GM" if against NPCS to get the first go just to set things up.
2. In larger groups vs smaller groups, I tend to have the larger groups not go any more than the smaller groups but have them do MORE STUFF on their turn so to speak. This is mostly so the PCs get to post often as well. As a GM you tend to need to post a lot, and sometimes it is best to dial down the detail a touch to get more things happening, and have more things happen per post so you aren't posting 3-4 times per PC post.
That may be difficult to do if the PCs are fighting in separate areas or against their own personal foe.
In Player vs Player, it is only fair everyone gets a posting turn unless otherwise discussed OOCly.
3. "Powerlevel" has a couple different ways to approach depending on the foes. When GMing Pathfinder or something, if the creature itself doesn't have an attack 'style' I will apply a personality to it.
Vulture: Goes after the weak (meaning low power level/injured people will get focused on and likely need help.)
Prideful: Goes after the strong as sense of pride of beating the big guy and not wanting to be seen as weak.
Guardian: Generally, goes after whoever is attacking one of its allies. This often will go after the leader as well.
Coward: Cheap shot guy, so once again may go after weak person.
Tactician: This one is more reading the battlefield and going after what seems the smartest at the time. (I avoid this one except for bosses and such because I don't want to "compete" against my players as the GM.)
(there are more I use but that is a sample.)
In general RP... this question flows quickly into 4.
4. If I am the one assigning the bad guys to fight certain people, I go for the way I think the players will enjoy the most. It may be being led by me, but it needs to have something for everyone, or at least something folks will enjoy. However, after I have 'assigned' in my own head who is going for who if the players change how I expected them to behave I roll with it... This could mean chaotic or more 1v1ish. A lot of times with mass combat if you are RPing the "fodder" I don't.... really treat the fodder with much concern. I let them be fodder and fall quickly... save for a few stronger ones.
5. Friendly fire... really is up to the people doing it. Sometimes a bad guy will sacrifice some lesser to get a good hit on a foe. As for player characters a lot of RP I have seen ends up with the line. "With friends like these who needs enemies."
6. Mass combat need patience from all parties. When you have fights with more than 3-4 people time between posting can get quite long. (The record I had was 1 hour... I cried) The "GM" often has to forgo detail and let the players have the fun with that until the combat thins out of the strong remaining. Often a solution is to have folks split off so they can continue their fights without having to wait for player B to post. (the 1v"1").
One RP I did I split the party into individuals at had their own enemies. It meant I was doing three times as many posts and my posts weren't as detailed as they could be, but it allowed the RP to keep a good pace and allowed each player to have as detailed posts as the wanted for their character. Then when they were brought together again, the combat style turned to 'fodder' where the 'scene' was set and then the players could include their kills in their posts so no one was waiting the GM between posts. Finally, it returned to a more organized posting order with the GM when the enemies were reduced to the strong and it needed a stronger guided hand.
Mass combat is very tricky due to the fact everyone has different styles of writing, different pace settings, and limited amount of patience. The other problem is we have fights that last an hour that in real time are 30 seconds if the detail is too great. In most films we see the protagonists in a mass battle and most everything around them is too chaotic to follow and people die left and right with little more than a stab, but then when they encounter a large strong foe the details of the fight get fleshed out and rest of the battlefield becomes a backdrop.
If we have all PC characters at once... you have too many "protagonists" for a cohesive and well paced battle if they are all together. Everyone wants lots of details... and the devil likes those.
Honestly... a "MASS BATTLE" between PC characters seems nigh impossible without splitting it into smaller chunks isolated from each other without running into mental limitations of players.
EDIT: As I find poor word choice this post may change.
