"The School of Athens"

Whenever a creature or player assembles a Contraption, you may roll a six-sided die. If you do, on a 6 or higher, you may assemble a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)
{5}, Tap three untapped creatures you control: Assemble a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)