Read this primary to get some concepts. Then learn MTG Rules on this.

Assuming {that a} change like this might additionally suggest you must pay prices out of your mana pool, relatively than with the ability to pay prices after placing a card on the stack (Otherwise, you get @Pow-Ian’s drawback), and must do it earlier than or throughout placing a card on the stack, it circumvents the issues with creating conditions for unlawful spells.

But it will get a bit extra concerned when sophisticated sequences are investigated. Namely, gamers must maintain precedence numerous the time so as to have the ability to pay prices throughout sequences when the stack is concerned. That would require this (often uncommon factor) to be stated lots, because it is not implied (for good causes, sometimes of sport movement).

The essential issues are these:

1. How unfriendly it will be to newer gamers, what number of “gotchas” it can create.
2. How everybody must be holding precedence on a regular basis.
3. Needing everybody to study the behavior of tapping lands earlier than casting spells, additionally inflicting many sport losses for trivial issues (casting an unlawful spell).
4. Sorcery velocity spells change into very arduous to make use of in quick(er) codecs. The culprits are bounce and discard results, that may reply to mana skills and both bounce lands or discard permanents. Vendillion Clique deserves a shout-out as a well-liked and already highly effective card that may actually abuse this by discarding the factor you are about to solid. Many playing cards would probably want bans as they flip into digital Time Walks..
5. Cards similar to Mana Leak, which requires an opponent to pay mana if you are casting a spell. Mana leak is difficult to anticipate, so now you possibly can’t go away 3 mana open to cope with it, you truly must over-fill your mana pool by 3 to stop the counter.

A clique instance

Player A Sacrifices Mishra’s bauble, naming Black. They faucet Forest, Plains, and Forest. Then, they go precedence with these skills on the stack. Player B casts Vendillion Clique, eradicating one in every of A’s two Siege Rhinos, and drawing them a card. The skills resolve, and A is left with GGW and holding the opposite Siege Rhino. They don’t have any swamps in hand, and might not solid Siege Rhino, and have missed a whole flip, whereas A will get a powerful creature.

A second instance

Player A has a 6/6 creature and a Silence. Player B has a pair of lightning bolts.

A assaults. During declare blockers, A passes precedence. B casts a lightning bolt, says they maintain precedence. Then B faucets a mountain to solid a second lightning bolt. A says “maintain on” and casts Silence. A choose known as, and the opposite lightning bolt is returned to B’s hand.

Why did this occur? Because participant B solely stated they maintain precedence as soon as, which meant it was used up by tapping the mountain.

Here’s one other one

At aggressive REL:

Player B: Island, Go.
Player A: Mountain. Tap mountain, Cast Lightning Bolt.
Player B: Wait, maintain on! Stifle. Judge, A solid Lightning Bolt with out having the mana. exhibits stifle. They did not say they had been holding precedence.

This thread has some extra examples

Tedious, gradual, and stuffed with feel-bad moments

Will change into of the popularity of this rule change. There’s all kinds of further gotchas instantly the place timing and precedence is anxious, making gameplay far trickier, as you must take into consideration holding precedence on a regular basis now, as a substitute of this being fairly a uncommon factor, you now sometimes need to say you are doing so with every land you faucet.

Basically the scenario now turns into that it is a good behavior to say you are holding precedence each time you are utilizing any mana potential. And mana skills are the most typical skills within the sport. This simply quadruples the variety of precedence passes in a sport. Say you curve out over 4 turns, attacking on the 4th. There’s often some 3 passes every flip (after casting every creature, the draw step, and saying “go” to finish your flip). But now you additionally get two precedence passes with every land tapped, including an additional 20 specific steps. It slows the sport down massively for little or no profit: 99% of the time, you get the mana anyway.

Conclusion

So whereas the foundations could be extra elegant within the sense of being extra temporary with having mana skills on the stack, and it could simply work by solely permitting cost from the mana pool, they’re actually no more sensible or extra pleasant. And these two issues trump magnificence.