In my school years I used to play a casual format with my friends we called „King and Flanks“ (german „König und Flanken“). Here is what I remember rule-wise:
You have two teams of three players each, with one king per team and two flanks (left and right). The each flank can only attack their opposing flank and once that player was dead the enemy king. The king can “send” their creatures through their flanks and can attack with the same abilities as either flank. The players have separate life totals, but share a turn (i.e. have to declare attackers at the same time).
What I am unsure about is how targeting spells and abilities work. Limiting the restrictions to attacking creatures seems unbalanced to me.
The format was a lot of fun, since slow decks can really shine as kings. We never build decks specifically for this format, this might have broken it.
Has anyone ever heard of such a format? What do you think the targeting limitations should be? Can someone point me to a source of this? I could not find anything on the internet.
I found a similar game mode, it's called emperor, you'll have to scroll down on the page a bit
https://magic.wizards.com/en/news/feature/casual-formats-2008-08-11
Emperor
The Emperor variant involves two teams of three players each. Each team sits together on one side of the table, with team members deciding the order in which they're seated. Each team has one "emperor," which is the player seated in the middle of the team. The remaining players on the team are "generals" whose job is to protect their emperor while attempting to take down the opposing emperor. Players randomly determine which emperor will go first, generally using the high roll on dice, and turn order then progresses to the left.
Emperors have a "range of influence" of 2, which means that their spells and abilities affect only themselves and players within two seats of their own. In other words, at the start of the game, they can affect everyone except the opposing emperor. Generals have a range of influence of 1. At the start of the game, they can't affect the opposing emperor either. The only way to get an opposing emperor within your range of influence is to defeat an opposing general!
Players may attack only opponents seated immediately next to them. This means that at the beginning of the game, emperors can't attack anyone because no opponent is sitting next to them.
Each player plays as an individual. Players can collaborate by looking at each other's hands and discussing strategy, but each player keeps a separate life total (starting at 20), hand, library, battlefield, and so on. The one difference is the "deploy creatures" option. Each of the emperor's creature has the ability "{T}: Target teammate gains control of this creature. Play this ability only any time you could play a sorcery." Keep in mind that when a player is eliminated from the game, all cards he or she owns (including creatures controlled by other players) are removed from the game. If that player controlled permanents that are owned by other players, they'll stay in the game and go back to whichever player should be controlling them now.
Winning and losing an Emperor game works differently than normal. A team wins the game when the opposing emperor has been eliminated. It doesn't matter whether the losing team has any generals remaining or not. This also means that a general that's been eliminated from the game can still win if his or her team eliminates the opposing emperor later on!
The Emperor format can be played with more than two teams; in that case, the appropriate Free-for-All rules are applied. The format can also be played with more than three members on each team, as long as each team has the same number. Each extra player on a team is an additional general. That means that some generals won't be sitting next to an opponent (they'll be between two teammates), so they can't attack anyone at the beginning of the game. Be sure to increase the range of influences accordingly.
