Okay, I admit it. I've been using the term Omniscient Gaming for quite some time now, and totally made it up. Here's another Red EFT passage explaining how it works....
Traditionally table-top gaming is Immersive or First-Person gaming. Each player at the table gets one character and while they are seated at the table they become that character. They use the character's name. They talk the way they imagine the character talking. Sometimes they even act the way the character acts. There is nothing wrong with this and much that is right about it, except that we are no longer living in the 1970's. For most people time is short and life is hectic. The people you gamed with last session may not be the same people you game with next session, so with omniscient gaming we sever those ties which so stiffly binds one player to one character.
Instead, your role in the game is more akin to a Greek god looking down from Mt. Olympus, watching events unfold in the mortal world and changing them through the actions of your favorite heroes. Your characters are your avatars, your presence in the world. They say what you want them to say, do what you want them to do. You roll the dice of fate on their behalf. Sometimes you even use your mojo to bend reality in their favor.
Your hand of characters is a fluctuating entity. While it is recommended that you never run more than five characters simultaneously, you can have characters come and go as they please. You can have characters make cameo appearances. You can swap them with your friends at the table and then swap them back again. You can even split the group, just so long as each player at the table has control over at least one of the characters who is heading off in a new direction.
Of course, it is important to remember that your characters represent living beings. When you are not playing them it is assumed they will be off doing pointless day to day stuff which is inconsequential to the adventure at hand. And by “come and go as they please” we mean that the character's come and go. You don't get to teleport them wherever you need them. Sorry.
Switching Characters. One thing you need to be careful about with omniscient gaming is to avoid confusion over who you are playing at any one time. If your characters are named Zitto, Penelope and Ralph then you should mention them by name whenever you switch between them.
Instead of saying “I walk up to the Barkeep and ask him if he has seen any Knights of the Black Orchid riding through town,” start with the name of the character who is speaking by saying “Penelope goes up to the Bartender and asks, 'Have you seen any Knights of the Black Orchid riding through town?'”
After identifying a character in this way you can switch into that character and start talking as if you are that character. Or you can just continue using a pronoun as you banter back and forth with the bartender. However, when you switch characters again you should re-identify yourself as the new character.
Communication. While you can talk to your friends sitting around the table it is good to remember that this is not the same as your characters talking to one another.
Character communication needs to be spoken aloud. If Dave is a friend of yours sitting across the table you shouldn't say, “Hey Dave, have Alphazar watch that window while Ralph tries to pick the lock on the chest.” Instead you should say, “Alright, Ralph says to Alphazar, 'hey will watch that window while I pick this lock?'” Changing your voice so you sound like Ralph (all rough and gravelly) while Ralph is speaking may also bring you some kudos.
Narration. In many ways omniscient gaming revolves around narrating your character rather than acting as that character. Feel free to mention things that normally wouldn't occur to an immersive gamer, such as the beads of sweat running down Ralph's forehead or his fingers trembling as he tries to pick that lock.
You cannot step outside of your realm of influence (which is Ralph) and say something like “he hears the tromping of boots in the hall.” Because unless the GM has already mentioned this it would be like you summoning up a troop of guards out of thin air. Most GM's however, will grant you significant liberty with the look and feel of the place, the ambiance of the situation.