Kaladesh: mechanics

Prerelease of Kaladesh starts on September, 24. This time there are no returning mechanics. Instead, we will get three totally new:

• Crew - each Vehicle starts out as just an artifact. Well, an artifact with some potential. It is keyword ability that enables vehicles to become artifact creatures until end of turn. To activate the crew ability, tap any number of creatures you control with total power equal to or greater than the crew number. Because the crew ability doesn't use the tap symbol, you can tap any untapped creature you control, even with summoning sickness. You can even tap an animated Vehicle to crew another Vehicle. Additionally, there is a 'Pilot' creature type, which usually gives Vehicle some bonuses, if it was tapped to pay the Crew cost. 
• Fabricate - when a creature with Fabricate enters the battlefield you may put a number of +1/+1 counters on the creature, or create a number of 1/1 colorless Servo artifact creature tokens. The number after fabricate tells you how many +1/+1 counters or Servos you get.
• Energy counters represent Aether, a magical energy that is found throughout the Multiverse and is an integral part of the ecosystem on Kaladesh. Energy counters are a new resource, placed on players in form of a counter, likewise Poison counters. They are used to pay the cost to activate abilities. Most cards that give you energy counters also give you a way to spend them. Energy counters that you get from one card can be saved up and spent on abilities of other cards. Energy counters don't go away, there is no 'energyburn' when a phase of your turn ends. The only way to lose them is to spend them.