Type 4 has five core concepts that are an embodiment of the format. The game is played with many variants within this framework, but these five fundamentals are what make Type 4 a semi-cohesive format. Any rules chosen beyond these five are malleable.
I: “Thou Shall Have Fun”
The most important guiding principle of Infinity Magic is that all players should enjoy the game. This is not a tightly-tuned competitive format, but rather a loud, gimmicky, and often ridiculous game. It’s almost a parody of Magic. Imagine if Commander was anything like how people describe it (splashy plays, expensive cards, stompy monsters), and that’s what Type 4 is like.
Towards this end, any rule that makes the game less fun should be ignored, and any cards that ruin the experience mean it should be discarded. This doesn’t mean when your salty friend starts to cry until you’re in floodpants because he lost to Pendelhaven Wurm that you take it out of the Stack. But talk to your players and use judgement and discussion in determining whether some cards are too good, oppressive, or unfun to play with.
II: “Thou Shall Have Infinite Mana”
Mechanically, the defining characteristic of Type 4 is that players have access to unlimited mana of all kinds, all the time. This means all colours, colourless, snow, and whatever other types of mana may emerge in the future. You have all that you want, all the time.
III: “Thou Shall Cast One Spell Per Turn”
During any given turn, a player may cast only one spell. Essentially, a game of Type 4 is played as though Arcane Laboratry or Role of Law is in play at all times. This is the great responsibility for your Commandment II’s great power.
One of the most common and best secondary rules in the format is an exception to this rule, which opens up the gameplay significantly, changing card valuation, options, and generally raising the skill and fun level without hurting the feel of the format.
IV: “Defensive Abilities Win In Infinite Loops”
When you have a set of rules as extreme as the ones above, there’s bound to be some strange circumstances during a game of Type 4. One of them might be one activated ability that only requires mana being countered by a similar ability. For example, Plaguebearer’s -X/-X ability against Morphling’s ability to Shroud itself. In this infinite stalemate, the defensive ability always takes precedent over the offensive ability. This allows play to continue even if both card remain on the board.
The clearest way I can word this is that if one ability is used to counter another, then the counter-ability takes precedent.
V: “Thou Shall Play From A Shared Card Pool”
If each player is assigned to bring a separate pile of cards to play Type 4 with, it could work in theory. It would require a LOT of organization, including agreement on how many cards, what cards were and were not acceptable for use, and various other terms. There’s an easier way to deal with this: a single player builds a ‘Stack’ or Type 4 collection, and all the participants use those cards to play games.
This still allows for a great deal of difference in Stacks. For example, some people might actually play with Fireball-like spells in a ‘touch of death’ type of Type 4 game, where counters and redirection spells are extremely common; this allows for tense, short games. Most traditional stacks avoid those type of effects.
Experiment and Explore
Those are the five basic rules. With them alone, you can play Type 4, but I strongly encourage you check out additional rules that will help flesh out the game, as well as some Game Types that bundle all the rules together for a complete experience.