Super Meter (or EX bar) is a very important thing in Mortal Kombat X. Using it in the appropriate way, with consideration, may be the key to success. The meter has been divided into 3 bars and it can be used to perform special moves, such as:
Moves that use up one bar of the Meter: If you want to enhance one of your moves, you can use up one of the three bars, to do that. To enhance the move, press the block button at the same time as the button allotted to the attack, for example (<,>+1+Block). If you press the attack button, and the block in a sequence, nothing will happen.
Moves that use up two bars of the Meter: Two bars of the Meter are used up by the Breaker (> +Block). It is a good move, if you have been caught by the combo of te opponent. To use the breaker, you also need to keep an eye on the Stamina Bar under the health bar. You can use the breaker only if you have two sections of the bar. Also, you need both if you want ot use the Block Breaker (two Stamina and EX Meter bars).
Moves that use up three bars of the Meter: X-Ray moves, which deal immense damage.
Using the Meter requires some practice, because even if you decide to use up the entire meter on the X-Ray only, and the opponent manages to block it, you will be at a disadvantage. It is much better an idea to enhance your special moves to combine them into combos.
Restoring the Super Meter: you load up the Meter by taking damage, but you can also charge by attacking the opponent, while he is blocking. Some of the characters can also use a special move to regenerate the Meter. If your opponent is blocking your attacks, he takes less damage, but you regenerate your meter, in exchange. Sometimes, this is useful. Especially that if the opponent is blocking, he does not regenerate his meter. It is worthy pointing out that the FIRST attack in the round gives your character one bar of the Super Meter.