Given the values \( a = a \), \( b = 3 \), and \( c = 0 \), we need to find the value of \( a^3 - bc \).
First, we calculate \( bc \): \[ bc = b \cdot c = 3 \cdot 0 = 0. \]
Now substitute \( bc \) into the expression \( a^3 - bc \): \[ a^3 - bc = a^3 - 0 = a^3. \]
Since \( a = a \), we can conclude that the expression simplifies to \( a^3 \).
Thus, the final answer is: \[ \boxed{a^3}. \]