This is not as simple as the title may sound haha. This has to do with rms/peak compared to amps.
So driver x calls for 100 watts rms. obviously anything under that will not hurt the driver. (Take clipping out of the picture for this example.) but to much power can blow the driver. An amp rating of 100 watts would be perfect for said speaker.
Question is how do people run 2-3 times the amount of power to a driver and it still operate properly?