Functional rules change

Starting with Amonkhet, the converted mana cost of split or aftermath cards will be amended. To ilustrate what exacly is changing let's take Wear/Tear card as a example. Soon, the converted mana cost of this card will be 3 if it is not on stack. Wear on the stack will have converted mana cost of 2 and Tear on the stack will have converted mana cost of 1.

What impact this change brings into Magic I can think of now:
- Wear/Tear is no longer a 1 and 2 CMC card (depending what you need), but it will always be 3 when revealed with Counterbalance.

- You can't imprint Fire/Ice with Isochron Scepter

- Cards enabling you to cast spell with converted mana cost less than X for free takes a hit (Cascade mechanic, Expertise cards and many, many more). You were able to cast either Research or Development using triggered ability of Goblin Dark-Dwellers.