@Kerrus your Whitewolf reverse-stack system seems useful, mainly because it seems to force players to immediately call at their actions (all of them) in rapid fire so that you can then go through and resolve the round. It seems to be a twice through system that should take double the length of time as an all-at once system like 3e. But its advantages seem to be enhanced reactions to lower initiative count actors. Can I get a more complicated example to highlight its other advantages over a forward ordered, turn by turn system?
Mostly my experience with it is that it requires the DM to do all the book keeping each round at the same time, rather than divvied up into smaller chunks. Depending on the combat situation this can make things easier or slightly more complex, but once you get used to the system I've found it really quite fun and useful for more dynamic combats. I never noticed combat rounds taking very much longer, outside of players who have no idea what they're going to do on their turn.
Additionally, the system handles massed combat much better than D&D, in which a player basically has to hope that his enemy can't hit him if he's facing a giant shitpile of mooks. But with this, there's a greater chance to react to things and handle mass combat.
For example.
The Good Guys are a ranger, a rogue, a monk, a paladin and a warlock.
The Bad guys are five mook rangers, three fighters, a paladin, a sorceror, and thirty angry peasants.
Everyone rolls for initiative, and the initiative track is as follows:
#3: 30 Peasants
#5: 3 Mook Rangers
#6: PC Paladin
#7: 2 Mook Rangers
#9: PC Warlock, NPC Paladin
#12: NPC Fighter #1, PC Rogue
#15: NPC Fighter #2, 3
#20: NPC Sorceror
#21: PC Monk, PC Ranger
Players can delay actions to beneath their initiative level if they desire, so they can wait until someone lower in the order has announced, and then do something after that action but before other stuff happens. Characters can take reactions/immediate actions/swift actions whatever at any point during resolution, but may otherwise only act on their init (or if they delay).
So the peasants announce first. Since they're basically a mob, half of them are going to charge the PCs, and the other half are going to try to encircle them.
Then it's three of the Mook Rangers, who all get their bows out and take individual targets.
Next up is the PC Paladin, who (assuming 4E) uses his divine sanction to mark everyone in 25ft for a round, which is like the whole encounter.
The two slightly quicker mook rangers decide to get their shots in at the Rogue and the Monk before the Paladin's mark goes off.
Next up, the NPC paladin and the PC Warlock have the same initiative. The NPC paladin is going to sanction the party for the round- but since the Warlock has a higher initiative modifier, the warlock gets to declare after. He uses baleful transposition to teleport the NPC paladin out of sanction range.
NPC fighter goes now- followed by PC rogue (higher init mod). The fighter charges the PC paladin. The rogue moves out of range of the angry peasants and fires a hand-crossbow at the enemy Sorceror.
The remaining NPC fighters go to gang up on the Rogue.
The NPC sorceror drops a carpet of adhesion on the party so they can't run away from the peasants.
The PC monk and PC ranger both focus fire on the sorceror.
So basically everybody announces what they're doing at each step. The DM asks them to keep that in mind so they can be 'on call' when he resolves everything. Once everything is declared, he moves to resolution.
"Monk, Ranger, roll your attacks." "I get a 19vs AC on my daily, and do 4d10b+3d6+2d8+25" "I get a 15 vs AC- no wait, that's a 17 because of CA- and do 8d10+4d8b+2d10+20" "Okay, your attacks both hit the enemy sorceror. He throws up his hands and tries to ward off your attack- but fails! You drop him to 0 HP, and he loses his action."
*DM turns to the rogue*
"Rogue, you have two angry fighters charging you with greataxes. You're currently trying to circle around away from the angry peasants. Any actions?" "Yeah, I use my immediate reaction to teleport three squares and become invisible." "Okay, you disappear, the fighters lose sight of you and waste their action, but you don't get your attack against the sorceror." "Okay, he's dead anyways."
"PC Paladin, you have an angry fighter charging you, what do?" "I raise my shield and tank the hit while invoking the divine power of my god, using an immediate reaction to add 5 to my AC." "Does a 20 still hit you?" "Nope." "Damn. The Fighter's attack crashes against your shield but you ward him off."
"Warlock, roll your check vs will defense." "Fifteen? No wait, +charisma because it's the first round. Twenty." "That hits. You teleport the NPC Paladin five squares in any direction." "I teleport him diagonally up." "*sigh* Okay, he falls twenty feet, takes falling damage, and is out of range for his sanction." "Nice!"
"Warlock, a brace of arrows peppers you. Does a 17 hit?" "Yeah." "Okay, you take 15 damage, and are poisoned. Roll a fortitude save." "8." "You failed. You lose 5 on your initiative at the start of the next round. Monk? The other two rangers attack you. 15 and 23." "The 23 hits- but I'm going to use deflect arrows as a reaction." "Roll it- that's a success." "I throw the arrow back at him." "You skewer him with his own ammunition, he takes 10 damage and drops."
"Now the peasants charge all of you, I'm going to do mass rolls here. Everyone list your AC." "23." "18." "19." "25." "15" "I'm still invisible!." "Right you are. Okay, those of you that aren't invisible get hit by approximately half the peasants using their improvised weapons. Each of you roll 3d6 and take that much damage. Paladin, your Divine Sanction triggers- do you want it to be lethal or non-lethal?" "Nonlethal!" "Okay, twenty six of the Peasants get knocked the fuck out. Next round!"
It might seem like it'd take longer, but basically all it does is shift individual resolution to the end of a combat round, which can make things easier from a tracking perspective because players have to keep track of less things. It also avoids some of the inter-round banter that sucks up time, and encourages players to think on their feet or have default actions that they follow. I'm also of the opinion that it makes combat more 'epic' or lively, with everything being way more dynamic and simulationist than it might otherwise be.