Not sure if can go here of if it should go in the Multiplayer forums, so apologies if not in the right place.
So in an Emperor game with 2 teams of 3, I get the Emperor can affect only two opposing generals and not the opposing Emperor, and the Generals can affect only their direct opposing General.
Generally, in Emperor games, "[s]pells and abilities can't affect objects or players outside their controller's range of influence" (C.R. 801.10, 801.1). Moreover, in such games, if "a spell or ability requires information from the game, it gets only information from within its controller's range of influence. It doesn't see objects or events outside" that range (C.R. 801.11, 801.1).
Thus, for example, in Emperor games, "all creatures", "all opponents", or "all permanents" on a spell or ability means only all creatures, opponents, or permanents, respectively, within the range of influence of the spell's or ability's controller.
EDIT (Dec. 20): Correction in quoted text.
EDIT (Mar. 23): Minor edit.
So in an Emperor game with 2 teams of 3, I get the Emperor can affect only two opposing generals and not the opposing Emperor, and the Generals can affect only their direct opposing General.
However
How do board wipes work?
How do cards work that say all opponents?
Thus, for example, in Emperor games, "all creatures", "all opponents", or "all permanents" on a spell or ability means only all creatures, opponents, or permanents, respectively, within the range of influence of the spell's or ability's controller.
EDIT (Dec. 20): Correction in quoted text.
EDIT (Mar. 23): Minor edit.