Z-Metal Tank, for example, says:
Once per turn, you can either: Target 1 "X-Head Cannon" or "Y-Dragon Head" you control; equip this card to that target.
It says other things, but this is enough to continue my question.
Can I activate this union effect when Z-Metal Tank is in my hand, as a sort of Special Summon, or can this only be done when it's already out on the field?
I guess this is a really basic question but neither the card text nor the beginner rule book accompanying the deck addresses this point.