This is a resurrection of an old Type 4 stack, updated with the latest sets

What the heck is "Type 4"???

Type 4 is the EDH of EDH. It's the pure rocket fuel format that you play when you're bored of playing the same efficient cards in EDH. It's a nonstop barrage of nonsense where game states change on a dime and no one can hold on to power too long.

Type 4 has the following rules:

• Each game starts with 4 players, and the players start with 30 life and only 5 cards in hand
• All players have I N F I N I T E   M A N A
• You may cast only ONE spell per turn
• Alternate casting costs for spells like morph creatures or Bringer of the Blue Dawn allow you to play one additional spell per turn
• Spells that cost 0 mana are free, and there's no limit on how many free spells you can cast per turn

There's a few questions that spring to mind when people hear that you have infinite mana...

• What about cards like.. Fireball or Torment of Hailfire??
  These cards aren't included in the cube, for obvious reasons. There should be no cards that singlehandedly win you the game outright so easily.
• Okay, what about the interaction of Vampiric Dragon and Armored Guardian? In a regular MTG game it's a stall, where one player can always respond to the activation of the opponent's creature.
  In these situations, "the tie goes to the defender". So there is no way for someone's Vampiric Dragon to kill their opponent's Armored Guardian.
• Fine, but aren't cards like Omniscience or Time Stretch too good?
  There are a lot of overpowered cards in this cube given the rule set. In fact there are 400 cards in this cube that are over powered. That's the point. No matter how strong a card is, there's a counter to it, and with 3 opponents who could very easily have an answer.. good luck.
• So what cards are good? There are some very old and obscure crappy cards that are suddenly great
  That's the fun part, figure it out for yourself! It's what we all did for EDH - look back through the history of Magic for the hidden gems that are suddenly now great. Only once you play a game or two of T4 do you truly realize what is strong and what is weak in the format.

You can just shuffle up the cards and hand out piles (after all, there are no lands to worry about, or color identity) or draft it to make a synergistic deck.