If you could move one mechanic from any system into any other system and make it part of the official rules, which mechanic would you move?
Some games have easier mechanics than others to move, but that's not super important for this. Just the idea behind the mechanic and what it does.
For me, I would move the ability to call Raises from Roll and Keep into....about every system I could. The ability for a PC to call their own criticals, to express their skill to get a better effect, is an amazing mechanic that more games could do with. it also gives a level of control to the player that I really appreciate.
Other systems have degrees of success, but Raises put that in the players control. You don't sometimes roll such that you had an amazing success. You go for the amazing success and either get it or fail. It also enables a character that is skilled beyond the difficulty of the task to really go for extra with it.
After all, how boring is it rolling when only 1 face of the die can make you fail just to make sure that doesn't happen? How much better would it be if you could make that difficulty higher, but in return get a benefit from it? Raises do that.
Fortunately, raises **can** be worked into other systems fairly easily if the mood strikes.
What about you?