Whir of Invention

Improvise can't pay for {W}, {U}, {B}, {R}, {G}, or {C} mana symbols in a spell's total cost.

When calculating a spell's total cost, include any alternative costs, additional costs, or anything else that increases or reduces the cost to cast the spell. Improvise applies after the total cost is calculated.

Equipment attached to a creature doesn't become tapped when that creature becomes tapped, and tapping that Equipment doesn't cause the creature to become tapped.

When using improvise to cast a spell with {X} in its mana cost, first choose the value for X. That choice, plus any cost increases or decreases, will determine the spell's total cost. Then you can tap artifacts you control to help pay that cost. For example, if you cast Whir of Invention (a spell with improvise and mana cost {X}{U}{U}{U}) and choose X to be 3, the total cost is {3}{U}{U}{U}. If you tap two artifacts, you'll have to pay {1}{U}{U}{U}.

Improvise doesn't change a spell's mana cost or mana value.