Micro Masters tend to be small, and they’ll often be outmatched on the battlefield. But that
doesn’t mean they can’t help your cause. They have tap abilities that give you an option other
than attacking with them.
Tap abilities all have the tap symbol (marked as [t] in text documents like this one) to the left
of the arrow.
You can use one tap ability during your turn, before you attack. It’s one of your turn actions,
just like playing an Action card, playing an Upgrade card, or flipping one of your characters to its
other mode. To use the tap ability, the character that has the ability must be untapped. Using
the ability causes the character to become tapped.
Does using a tap ability also mean the character attacks?
[Source: WotC] 
No. Using a tap ability isn’t the same as attacking.
No. It’s your choice. You don’t have to use a tap ability, even if you could.
If I have more than one untapped character with a tap ability, can I use all of them in the
same turn?
[Source: WotC]
No. You can use only one tap ability per turn.
Can I use a tap ability, then play an Action that untaps that character, then use that tap
ability again?
[Source: WotC]
Nope. One tap ability per turn.
Some tap abilities say I have to scrap cards from my hand or other additional costs. Can I use
a tap ability if I can’t pay that cost.
[Source: WotC]
No. For example, if a tap ability says you have to scrap a card from your hand with an orange
battle icon, and you don’t have one, you can’t use that tap ability.
How do I use a Micromaster’s tap ability? Let's say Raider Detour. I tap Raider Detour, then scrap a card with a blue battle icon, and draw my 2 cards. Does that mean I have used Raider Detour and now I attack with one of my other characters?
[Source: WotC]
You can still play an Action or Upgrade if you haven’t and would like to, but then you can move on. Each turn, you can use one tap ability. Raider Detour will not be able to attack because he is tapped. However if he were untapped somehow, he would still be able to attack.
If I’m defending with
Raider Visper, who is untapped, and my opponent plays
EMP Wave, do I get the option of discarding 3 green pips to force them to discard 3 cards? If they’re matching, do I get to draw three? Also, EMP Wave would always make it the turn of the person who didn’t play it, correct? Or if I’m attacking and play EMP Wave do I get to swing with a character that I just tapped?
[Source: WotC]
No, a Tap ability is something you use on your turn, not whenever the character becomes tapped. If you play
EMP Wave on your turn, all characters will be tapped. Your turn continues, and you can play an upgrade, flip a character, etc. At the end of your turn, all characters will untap, and your opponent’s turn will begin.
